•Pentacene-OPT with Au electrodes obtains higher photoresponsivity than that with Al.•CuPc-OPT with Al Shottky contact achieves a higher PMAX than that with Au electrodes.•The improved PMAX effects in Al-CuPc-OPT can be ascribed to PIBL effect.•The physical mechanism of photon induced barrier lowering in OPT was studied.•Schottky barrier of source-drain/active layer plays a beneficial role in some OPTs.In order to clarify the influence of the source/drain (S/D) electrodes/the active layer contact condition on the photoelectric properties of the organic phototransistor (OPT), pentacene (Pn) and copper phthalocyanine (CuPc) based OPTs with Au or Al as S/D electrodes were fabricated. The output and transfer characteristics of OPTs were investigated in the dark and under illumination. The results indicate that high-mobility Pn-OPTs are more suitable for the use of Au electrode with low contact barrier to obtain higher photoresponsivity. And low-mobility CuPc-OPTs are more suitable for the use of Al electrode with Shottky contact for maintaining the same level of photoresponsivity while achieving a high maximum photosensitivity (PMAX). Compared with Au-CuPc-OPT, the improved PMAX effects of Shottky contact on Al-CuPc-OPT can be ascribed to the photon induced barrier lowering (PIBL) effect after illumination. The physical mechanism of PIBL in OPT was deduced in this paper.

•The performance of PbPc single-layer NIR organic phototransistor was improved with different-thickness CuPc template inducing layers (TILs).•Different-thickness CuPc TILs present different template inducing effects.•2.5-nm CuPc TIL which is quasi-continuous and highly ordered approximate-monolayer produces an optimal template inducing effect.Organic phototransistors (OPTs) have captured a growing attention over the years due to their advantages of lightweight, flexibility, low cost and large area fabrication. Especially, how to improve the single-layer device performance is an essential issue. Here, we report that the performance of lead phthalocyanine (PbPc) single-layer near-infrared OPT was improved by inserting different-thickness (1, 2.5, 5 and 8 nm) copper phthalocyanine (CuPc) template inducing layers (TILs). We found that different-thickness CuPc TILs present different continuity and the corresponding PbPc films show different crystallinity, exhibiting different template inducing effects. The maximum mobility, photoresponsivity, specific detectivity and photosensitivity of 8.6 × 10−5 cm2V−1s−1, 2.3 A/W, 4.0 × 1011 Jones and 82.7, respectively, were obtained when the thickness of CuPc TIL is 2.5 nm rather than that of 0, 1, 5 and 8 nm. This may be because the 2.5-nm CuPc TIL that is quasi-continuous and highly ordered approximate-monolayer produces an optimal template inducing effect, and therefore the upper PbPc film holds the highest triclinic crystallinity and content, resulting in the highest carrier mobility and the highest near-infrared light absorption efficiency in the series of OPTs. This work can provide a guideline for improving the performance of single-layer organic photodetectors.

•The high-quality and fine electronic structure of monolayer MoS2 is obtained by using CVD synthesis.•Monolayer MoS2 (2D material) combined with organic materials (pentacene) is in application to the photoelectric devices.•The photoresponsive field-effect transistor based on MoS2/pentacene exhibited an ultrahigh photoresponsivity of 103 A/W at Popt = 0.01 μW.Monolayer molybdenum disulfide (MoS2), with a high predicted intrinsic mobility of ∼410 cm2/V at room temperature, shows great potential for application in sensors and optoelectronics as a result of good electrical performance and photoemission. Compared with the photoresponsive photodiodes, photoresponsive field-effect transistors exhibit higher sensitivity and lower noise. And, pentacene is a small molecule organic semiconductor and has high absorption in the visible region. Here, we reported on a high-performance photoresponsive field-effect transistor based on MoS2/pentacene inorganic/organic planar heterojunction. The results showed that the device demonstrated superior performance. Under 655 nm light illumination, the device exhibited an ultrahigh photoresponsivity of 103 A/W, a maximum photosensitivity of 1.8 × 103 and a high external quantum efficiency of around 195%, respectively.Download high-res image (233KB)Download full-size image

•The broadband photodetector achieves an extremely high on/off value 3.6 × 106 and accompanies with detectivity 3.1 × 1013.•The devices have a high photoresponsivity of 11.5 A/W or ∼0.01 nA dark current which leads to a high on/off value.•Even the photodetectors operate under a weak power illumination such as 0.08 mW/cm2, they can still get 210 nA photocurrent.Broad absorption bandwidth photodetectors based on organo-metal halide perovskite absorbers is an attractive means of resolving the narrow absorption of organic semiconductors. Here we report the achievement and characterization of broad spectral photodetectors based on CH3NH3PbI3−xClx, which has been optimized with four different electrodes and a specially modified highly crystallized active layer. This work use six different lasers which wavelength range from ∼405 nm to ∼808 nm as the illuminations, and shows clearly that the Au electrode devices have ultrahigh photosensitivity (P=IphIdark=Iill−IdarkIdark, up to 3.5 × 106 at incident light power of 38 mW/cm2) and such low dark current of ∼0.01 nA at −10 V. In addition, we achieved a relatively high photoresponsivity of 11.5 A/W at incident optical power ∼0.8 μW/cm2 for Ag electrode devices. Furthermore, this work demonstrates that the devices of Al electrode have an unexpected low performance, which has been proved to be caused by serious oxidization through XPS test results, this unpopularity may due to the roughness morphology at the interface and instability of Al chemical property. Our work will provide a strategy to fabricate facile and ultrasensitive broadband photodetectors with perovskite as absorber and several familiar metals as electrodes.Download high-res image (255KB)Download full-size image

Recently, broad spectral response phototransistors have drawn substantial attention due to their applications in the field of industry and science. However, it is difficult to synthesize appropriate photosensitive materials, which greatly limits their development. Integrating multicomponent bulk heterojunctions with high mobility materials to form hybrid planar-bulk heterojunction is a very effective approach to overcome these shortcomings. Herein, we reported broad spectral response photosensitive organic field-effect transistors with tricomponent bulk heterojunctions (Tri-BHJ) and high mobility channel transport layer, and they were sensitive over a bandwidth from ultraviolet–visible to near infrared. The Tri-BHJ composed of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), chloroaluminum phthalocyanine (AlClPc) and lead phthalocyanine (PbPc) was used as the photosensitive layer, fullerene (C60) as the channel layer, and SiO2 as the gate dielectric. By replacing SiO2 with polyvinyl alcohol (PVA), the device performance was improved significantly, and the photosensitivity, photoresponsivity, external quantum efficiency and specific detectivity of the device built on PVA dielectric reached up to 105, 108.44 A/W, 25325% and ∼2.7 × 1012 Jones, respectively, which are comparable or even superior to those of commercially silicon and indium gallium arsenide photodetectors or other reported organic photodetectors. This work indicated new directions for the future development of high performance broad spectral response phototransistors.Broad spectral response photosensitive organic field-effect transistors are realized by integrating tricomponent bulk heterojunctions with high mobility fullerene channel layer to form hybrid planar-bulk heterojunction and mutual-complementary spectra, achieving high photoresponsivity from UV–Vis to NIR region.Download high-res image (271KB)Download full-size image

Broadening the absorption bandwidth of photodetectors by incorporating multiple absorber materials to form bulk-heterojunction active layers is an attractive method of resolving the narrow absorption of organic semiconductors. Here we report the fabrication and characterization of broad spectral hybrid organic–inorganic photodetectors through an optimized multiple component organic bulk heterojunctions route. The study clearly shows that both the two-component and three-component photodetectors have ultrahigh photosensitivity and spectral uniformity of responsivity for visible to near-infrared light. Operating at room temperature, the three-component based photodetectors achieve ultrahigh photosensitivities of 30–50 A W−1 at ∼0.1 mW incident optical power, which are almost two orders of magnitude larger than commercial Si and InGaAs photodiodes. Also, this work demonstrates that the wide variation of optical absorption of multiple component organic bulk heterojunctions will provide a strategy to fabricate facile broadband photodetectors.

Organic phototransistor (OPT) is a promising organic device with substantial attention due to its photodetection combined with lightweight, flexibility, large-scale yields, and low cost of organic materials. In addition, spectral tunability and long photocarrier lifetime for organic materials make them highly attractive for advanced optoelectronic device applications. Here, we report high-performance broadband photodetection devices fabricated using an all-organic heterojunction of fullerene/chloroaluminum phthalocyanine with a high-efficiency exciton-dissociation-interface and complementary spectral absorption. Operating at room temperature, the prepared OPTs offer broadband ultraviolet–visible–near infrared spectral response, exhibiting ultrahigh photoresponsivity of 94.4 A/W, the highest detectivity ∼1.5 × 1013 Jones combined with external quantum efficiency of 26,066%, and the ability to measure high-frequency signals. These parameters are comparable or even superior to commercially available silicon carbide, silicon and indium gallium arsenide photodetectors, indicating the possibility of many applications based on broadband detection utilizing our devices. A semi-quantitative calculation and energy level mechanism reasonably explain the ultrahigh performances above. Our results suggest that organic compounds with mutual complementary spectra can be used for constructing photosensitive active layer, in which optimized interfacial electronic structure and morphology help photoexciton dissociation and extend the spectral response range.

The electrical and optical properties of organic semiconductors have improved rapidly in recent years, rendering them highly promising for various optoelectronic applications owing to low-cost and lightweight potential in combination with spectral tunability and long photocarrier lifetimes. Organic photomemory has emerged as an innovative application to achieve optical data storage. However, practical operation requires universal device design with broader spectral response in terms of related materials, interfaces and architecture, a task that remains a significant challenge. Herein, we present a universal strategy to fabricate organic broadband photomemories featuring remarkable UV-NIR response, thereby providing optical switching ability with a controllable memory window. To the best of our knowledge, this study demonstrates an excellent performance with the broadest response spectra and the highest photomemory efficiency of up to 593%. We systematically study the charge trapping mechanism and photoinduced injection enhancement by combining an energy level model with theoretical calculations, characterizing conceivable photogenerated minority carrier trapping and accumulation kinetics. Thus, it is anticipated that the proposed approach will be a starting point for further research, resulting in high-performance organic photomemory ideal for digital commutation between optical and electric signals.

•We propose the design principles of organic NIR upconversion devices.•Upconversion devices are realized integrating NIR-sensitive PHJs and inverted OLEDs.•We fabricate and study photo-generated electron and hole based upconversion devices.Optical upconversion devices up-converting near-infrared (NIR) light to visible light have attracted a great deal of research interest in the past decades. Among these devices, organic upconversion devices have been presented as an alternative strategy for simplifying the fabrication process and reducing the cost. In recent years, along with the development of organic electronics, several types of organic NIR upconversion devices have been reported. However, there have been very few systematic studies of the design principles and operation mechanisms of organic NIR upconversion devices. In order to illustrate the structural design principles and operation mechanisms, organic upconversion devices based on donor/acceptor planar heterojunction (PHJ) as NIR sensitizer and inverted OLED structure as emitter are fabricated and studied. Significantly, two types of photo-generated electron and hole based organic upconversion devices are realized by ingeniously exchanging the position of the PHJ and the inverted OLED in the devices, respectively. The light emission in the former results from the recombination of photo-generated electrons with the injected holes from the anode, while that of the later from the recombination of photo-generated holes with the injected electrons from the cathode. Both types of the upconversion devices demonstrated great potentials for future pixel-less NIR imaging applications.

•ErPc2 film exhibits considerable absorption in the NIR region.•ErPc2 is suitable as NIR photoresponsive layer of PhOFETs.•The heterojunction devices show superior performance to the single-layer ones.•Pentacene/ErPc2 PhOFETs show a photoresponsivity of 6.5 A/W under 808 nm light.Near-infrared photosensitive organic field-effect transistors (PhOFETs) based on pentacene/erbium phthalocyanine (ErPc2) and copper phthalocyanine (CuPc)/ErPc2 heterojunction, as well as ErPc2 single-layer PhOFETs, were fabricated and characterized. The results showed that the heterojunction PhOFETs exhibit higher mobility, maximum photoresponsivity (Rmax) and maximum photo/dark current ratio (Pmax), comparing with the ErPc2 single-layer ones. Such a better performance of the heterojunction devices can be attributed to the higher mobility channel layer. And the pentacene/ErPc2 PhOFETs demonstrate an Rmax of 6498 mA/W, Pmax of 2.6 × 103, hole mobility of 1.5 × 10−2 cm2 V−1 s−1 and excellent air stability, its Rmax is 186 times larger than that of the ErPc2 single-layer PhOFETs. Therefore, ErPc2 can be used as an excellent NIR photoresponsive layer of heterojunction PhOFETs.

A double-gate organic field-effect transistor (DGOFET) utilizing thermally evaporated lithium fluoride (LiF) as the top gate dielectric and fluorinated copper-phthalocyanine (F16CuPc) as the active channel material was reported in this article. XRD and AFM analyses manifested that the fabricated LiF films on the F16CuPc channel layer were highly dense polycrystalline, uniform, and flat. A comprehensive and systemic study of operational dynamics and architecture dependence of DGOFETs was reported herein. Three different operating modes of DGOFETs were introduced and demonstrated, which indicated that controllable device performances (considering output current, threshold voltage, etc.) could be obtained by double-gate architecture, and DGOFETs working in the synchronized mode exhibited high field-effect mobility, low threshold voltage (absolute value), and large transconductance. Furthermore, the DGOFET based F16CuPc showed a better gate modulation effect, which could achieve a switch from normally-on to off-state in double-gate mode. The successful operation of the fabricated DGOFETs also indicated that LiF is a promising material as the dielectric for realizing high-performance and patterned top-gate OFETs.

•Single-layer PbPc device performance is raised by adding pentacene inducing layer.•An optimal inducing layer thickness is proved ∼2 nm.•The 2-nm-thick inducing layer produces the strongest template inducing.Lead phthalocyanine (PbPc) based photosensitive organic field effect transistors (PhOFETs) with different-thickness pentacene inducing layers (INLs) inserted between SiO2 and PbPc layer were fabricated and characterized. The photoelectric measurements demonstrate that the device with 2-nm-thick pentacene INL exhibits the largest photoresponsivity of 505.75 mA/W and maximum photo/dark current ratio of 405.35 in all devices. For this, we give an overall explanation that different-thickness INLs display different continuity and crystallinity and thus produce strong or weak template inducing. Especially, when the INL thickness (δ) is 2 nm a quasi-continuous and highly crystalline approximate-monolayer INL forms on SiO2 surface, which may play a strong role of template inducing, thus causing its upper PbPc film to demonstrate the strongest triclinic (3 0 0) line and the strongest NIR absorption in series PbPc films. When δ = 1 nm, pentacene does not form a continuous film. And when δ = 5 or 10 nm, a continuous multilayer INL with a declined crystallinity due to possible lattice mismatch forms on SiO2 surface and gives a weakened template inducing. Thereby, it can be recognized that inserting a pentacene INL can markedly enhance the performance of single layer PbPc PhOFET and the optimum INL thickness is proved ∼2 nm in present conditions.

•The proportion of triclinic phase in PbPc films increases with rising Tsub.•The film grains get larger with rising Tsub.•The increasing proportion of triclinic phase causes a stronger NIR absorption.•The enlarged film grains give a higher carrier mobility for Tsub ≤ 140 °C.•An optimal device performance is provided at Tsub = 140 °C.In order to study the dependence of device performance on substrate temperature (Tsub), lead phthalocyanine (PbPc) photoresponsive organic field-effect transistors were fabricated at different substrate temperatures and characterized. We observed as Tsub rises, the photoresponsivity (R) and the maximum photo/dark current ratio (Pmax) of the devices first increase and then decrease, and an optimal device performance is provided at Tsub = 140 °C, at which the R and Pmax of the device reach maximum simultaneously. This is mainly a result of competition between the enhanced NIR absorption originating from the increasing proportion of triclinic phase in PbPc films with rising Tsub and the decreased carrier mobility at higher substrate temperatures, as evidenced by optical absorption spectrum, X-ray diffraction and atomic force microscopy investigations.

•The C60 buffer layer thicknesses of the modified pentacene-OPTs were further optimized.•The optimized buffer layer thickness increases with the increasing of the surface roughness of the active layer in OPTs.•An important parameter, saturated photoresponsivity, which can be used for comparing the performances of OPTs was introduced.Inserting a C60 buffer layer between Au source/drain electrodes and pentacene active layer has been proved to improve the performances of pentacene organic phototransistors (PENT-OPTs) in our previous study. Buffer layer certainly has an optimal thickness with which the modified device can achieve the best performance. Based on the surface morphology analysis of different thickness C60 buffer layer on pentacene film, we further optimized the thickness of C60 buffer layer for best performance of PENT-OPTs and investigated its physical origins. Studies on PENT-OPTs with different pentacene surface morphology realized by different substrate temperatures indicate that the optimal thickness of C60 buffer layer directly related to the surface roughness of pentacene active layer and it is found that the optimized buffer layer thickness increases with the roughness of pentacene layer. Besides, we found that the photogenerated current of OPTs increases with the increasing of gate electric bias and then gradually reach saturation. An approximate analytical expression for gate voltage dependence of the photogenerated current was derived and used to fit the experiment data. An important parameter, saturated photoresponsivity, was introduced for better comparing the performances of OPTs.

Compared with organic photodiodes, photoresponsive organic field-effect transistors (photOFETs) exhibit higher sensitivity and lower noise. The performance of photOFETs based on conventional single layer structure operating in the near infrared (NIR) is generally poor due to the low carrier mobility of the active channel materials. We demonstrate a high performance photOFETs operating in NIR region with a structure of hybrid planar-bulk heterojunction (HPBHJ). PhotOFETs with the structures of single layer [lead phthalocyanine (PbPc) or copper phthalocyanine (CuPc)], single planar heterojunction (PHJ) of CuPc/PbPc, double PHJ of CuPc/PbPc/3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and HPBHJ of CuPc/PbPc:PTCDA were fabricated and characterized. It is concluded that the photOFET with HPBHJ structure showed superior performance compared to that with other structures, and for NIR light of wavelength 808 nm, the photOFET with HPBHJ structure exhibited a large photoresponsivity of 322 mA/W, a high external quantum efficiency of around 50%, and a maximal photosensitivity of 9.4 × 102. The high performance of HPBHJ photOFET is attributed to its high exciton dissociation efficiency and excellent hole transport ability. For 50-nm thick CuPc layer, the optimal thickness of the PbPc:PTCDA layer is found to be around 30 nm.Graphical abstractHighlights► The mobility of infrared (NIR) sensitive organic materials is generally low. ► Performance of conventional NIR sensitive organic field-effect transistors (photOFETs) is poor. ► We fabricated NIR photOFETs based a structure of hybrid planar-bulk heterojunction (HPBHJ). ► We demonstrate that the performance of HPBHJ photOFETs is superior than conventional ones. ► HPBHJ photOFET exhibited a large photoresponsivity of 322 mA/W for 808 nm NIR light.

The effects of the incident light intensity, the thicknesses of the donor and acceptor layers on the short-circuit current density, the distributions of carrier density, electric field and electric potentials of planar heterojunction organic solar cells were numerically studied. The results show that the short-circuit current density increases with the light intensity, and will saturate when the light intensity is sufficiently strong, the short-circuit current density first increases and then decreases with the thickness of the donor layer for a given thickness of the acceptor layer, and deceases with the acceptor thickness for a given thickness of the donor layer.

Among the many possible device configurations for organic memory devices, organic field-effect transistor (OFET) memory is an emerging technology with the potential to realize lightweight, low-cost, flexible charge storage media. In this feature article, the recent progress in the classes of OFET-based memory, including floating gate OFET memory, polymer electret OFET memory, ferroelectric OFET memory and several other kinds of OFET memories with unique configurations, are introduced. Finally, the prospects and problems of OFETs memory are discussed.

We present a numerical study of the effects of the energy barrier between the lowest unoccupied molecular orbital of the acceptor layer and the cathode, the thicknesses of the donor layer and acceptor layer on the distributions of carrier density, the electric fields and the electric potentials of organic planar heterojunction solar cells. We obtained the quantitative dependencies of the distribution of carrier density, electric fields and the electric potentials on these quantities. The results provide a theoretical foundation for the experimental study of open-circuit organic planar heterojunction solar cells.

This paper presents a systematic numerical simulation of variation of blending ratio and cathode work function dependence of poly(2-methoxy-5-(3′,7′-dimethyloctyloxy)-para-phenylene vinylene) (MDMO-PPV):phenyl-C61-butyric acid methyl ester (PCBM) bulk heterojunction (BHJ) solar cells performance for MDMO-PPV concentration between 0 and 100 mol percentage and cathode work function interval 3.7–4.7 eV. From our studies it became evident that the open-circuit voltage (Voc), short-circuit current (Jsc) and fill factor (FF) decrease with the increasing cathode work function. It is shown that Jsc increases almost linearly with the increasing MDMO-PPV concentration from 0 to 60 mol%, and then decreases. With the increasing of MDMO-PPV concentration, FF augments gradually to 76.56% and then plunges to 19.53%. It is also demonstrated that when MDMO-PPV is larger than 45 mol%, the enhancing MDMO-PPV mol percentage is detrimental for the device performance.

The influence of the cathode work function, carriers mobilities and temperature on the short-circuit current of single layer organic solar cells with Schottkey contacts was numerically studied, and the quantitative dependences of the short-circuit current on these quantities were obtained. The results provide the theoretical foundation for experimental study of single layer organic solar cells with Schottkey contacts.

Under the basis of Gaussian energy distributions of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), analytical expressions of generalized Einstein relation for electron and hole transport in organic semiconductor thin films are developed. Numerical calculations show that, although traditional Einstein relation is still valid for low carrier concentrations, when the carrier concentration is high, the diffusion coefficient–mobility ratio increases rapidly with the carrier concentration. A relative turning carrier concentration, characterizing the upper limit of the validity of traditional Einstein relation is defined. The dependences of the relative turning concentration on the variance of LUMO or HOMO energy distributions as well as the sample temperature, and the applications of the generalized Einstein relation in the analysis of organic light-emitting device are discussed.

Broadening the absorption bandwidth of photodetectors by incorporating multiple absorber materials to form bulk-heterojunction active layers is an attractive method of resolving the narrow absorption of organic semiconductors. Here we report the fabrication and characterization of broad spectral hybrid organic–inorganic photodetectors through an optimized multiple component organic bulk heterojunctions route. The study clearly shows that both the two-component and three-component photodetectors have ultrahigh photosensitivity and spectral uniformity of responsivity for visible to near-infrared light. Operating at room temperature, the three-component based photodetectors achieve ultrahigh photosensitivities of 30–50 A W−1 at ∼0.1 mW incident optical power, which are almost two orders of magnitude larger than commercial Si and InGaAs photodiodes. Also, this work demonstrates that the wide variation of optical absorption of multiple component organic bulk heterojunctions will provide a strategy to fabricate facile broadband photodetectors.

A double-gate organic field-effect transistor (DGOFET) utilizing thermally evaporated lithium fluoride (LiF) as the top gate dielectric and fluorinated copper-phthalocyanine (F16CuPc) as the active channel material was reported in this article. XRD and AFM analyses manifested that the fabricated LiF films on the F16CuPc channel layer were highly dense polycrystalline, uniform, and flat. A comprehensive and systemic study of operational dynamics and architecture dependence of DGOFETs was reported herein. Three different operating modes of DGOFETs were introduced and demonstrated, which indicated that controllable device performances (considering output current, threshold voltage, etc.) could be obtained by double-gate architecture, and DGOFETs working in the synchronized mode exhibited high field-effect mobility, low threshold voltage (absolute value), and large transconductance. Furthermore, the DGOFET based F16CuPc showed a better gate modulation effect, which could achieve a switch from normally-on to off-state in double-gate mode. The successful operation of the fabricated DGOFETs also indicated that LiF is a promising material as the dielectric for realizing high-performance and patterned top-gate OFETs.

The electrical and optical properties of organic semiconductors have improved rapidly in recent years, rendering them highly promising for various optoelectronic applications owing to low-cost and lightweight potential in combination with spectral tunability and long photocarrier lifetimes. Organic photomemory has emerged as an innovative application to achieve optical data storage. However, practical operation requires universal device design with broader spectral response in terms of related materials, interfaces and architecture, a task that remains a significant challenge. Herein, we present a universal strategy to fabricate organic broadband photomemories featuring remarkable UV-NIR response, thereby providing optical switching ability with a controllable memory window. To the best of our knowledge, this study demonstrates an excellent performance with the broadest response spectra and the highest photomemory efficiency of up to 593%. We systematically study the charge trapping mechanism and photoinduced injection enhancement by combining an energy level model with theoretical calculations, characterizing conceivable photogenerated minority carrier trapping and accumulation kinetics. Thus, it is anticipated that the proposed approach will be a starting point for further research, resulting in high-performance organic photomemory ideal for digital commutation between optical and electric signals.