A Highly Sensitive Perovskite/Organic Semiconductor Heterojunction Phototransistor and Its Device Optimization Utilizing the Selective Electron Trapping Effect

Abstract

Hybrid organic–inorganic perovskite materials have recently attracted attention due to their impressive physical properties and promising application in future optoelectronic devices and systems. In this study, a high‐performance and broadband photodetector comprising vertically stacked Cs‐doped formanidinium lead iodide (FAPbI3) perovskite/dinaphtho[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene heterojunction, which shows a high responsivity of 778 A W−1 and a specific detectivity of 1.04 × 1013 Jones, is reported. In addition, the photodetector displays excellent stability and broadband responsivity to illumination ranging from deep‐ultraviolet to near‐infrared light. It is interesting to note that doping a small amount of [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) into the perovskite film results in a substantial increase in responsivity, specific detectivity, and photoconductive gain. Specifically, the specific detectivity is as high as 7.96 × 1013 Jones, which is much higher than that of other devices with similar geometries. The device optimization can be ascribed to an enhanced electron–hole separation ability and increase in electron accepting sites that can selectively trap electrons in the perovskite–PCBM bulk heterojunction, according to results from the experimental analyses.

Ultrasonically Exfoliated Nanocrystal-Based Z-Scheme SnSe2/WSe2 Heterojunction for a Superior Electrochemical Photoresponse

“…Meanwhile, the value of R λ decreases from 1.03 to 0.45 mA W −1 when the power intensity increases from I 1 to I 5 , respectively, due to a fewer number of trap states that are available for a large number of charge carriers generated under high power density, which increases the recombination rate. 43 This indicates the potential of the prepared PEC photodetector under low power intensity.…”

Solution-Processed Uniform MoSe2–WSe2 Heterojunction Thin Film on Silicon Substrate for Superior and Tunable Photodetection

“…Figure c demonstrates the variation in photocurrent and responsivity as a function of illumination intensity. The value of R λ decreases with increasing intensity due to a limited number of trap states are present in comparison to photogenerated charge carriers, which strengthened the recombination rate. , The results suggest the potential and productivity of the device under low illumination intensity. Meanwhile, we have also investigated the pulse photoresponse of MoSe 2 –WSe 2 /Si heterojunction at a different temperature ranging from 300 to 45 K as shown in Figure S5.…”

Vertical Channel Inorganic/Organic Hybrid Electrochemical Phototransistors with Ultrahigh Responsivity and Fast Response Speed

“…Organic phototransistors (OPTs) have received increasing attention for application in imaging sensors and optical communication as they combine high photoelectric performance with cost-effective fabrication, lightweight, and flexibility. − The performance of OPTs is mainly governed by device systems including the optoelectronic materials properties and device properties (e.g., architecture, transconductance, and conductance) . To improve their performance, substantial efforts have been dedicated to optimize materials systems by using a variety of material heterojunctions that are advantageous for exciton dissociation and carrier transport − and by developing various materials with micro-/nanostructures including nanoparticles, nanowires, and nanosheets. − Consequently, impressive progress has been made on the development of highly sensitive and fast response OPTs. In addition to the optoelectronic materials, device properties are also essential in determining the performance of the phototransistor.…”