UV and Visible Photodetectors of MAPbBr₃ and MAPbCl₃ Perovskite Single Crystals via Single Photocarrier Transport Design

Abstract

Understanding photogenerated charge transport is critical to further improving the performance of perovskite‐based devices. In this study, the low‐defect perovskite CH3NH3PbX3 (X = Br or Cl) single crystals, which are an ideal platform for high‐quality optoelectronic devices, are fabricated to examine characteristics of photodetectors with electrodes with Au or Ag, and interlayer of TiO2. The transport mechanism of the photogenerated carriers in each device is elucidated by analysis of the current density–voltage curves under dark or a 405 nm of super‐bandgap illumination or a 640 nm of sub‐bandgap illumination. The photocurrent under the 405 nm illumination is improved under the hole‐dominant Au‐device of p‐type bromide crystals and the electron‐dominant Ag‐device of n‐type chloride crystals. The defect‐assisted excitation under 640 nm illumination is associated with generation of the holes with the defects located near the conduction band or the electrons with the valence band in each perovskite materials. With this conception, the responsivity of 0.07 A W−1, specific detectivity over 1011 Jones, and external quantum efficiency around 16% are obtained in the best performing devices. The present results suggest a promising strategy for designing efficient photodetectors using photogenerated and trap‐assisted photocarriers that contribute to enhanced photocurrent.

Zwitterions in 3D Perovskites: Organosulfide-Halide Perovskites

“…The weak room-temperature PL, measured by timecorrelated single photon counting (TCSPC), exhibits an instrument response-limited component followed by a 0.9 ns decay (Figure 5B), which is similar to the PL lifetime of a (MA)PbCl 3 crystal (1.6 ns). 31,32 Some variation in the PL lifetime of different crystals (0.9−3.1 ns) is consistent with a defect-mediated emission.…”

High performance of CH3NH3PbCl3 perovskite single crystal photodetector with a large active area using asymmetrical Schottky interdigital contacts

“…The active area of the device is around 8 mm 2 , which is one of the largest active area for reported CH 3 NH 3 PbCl 3 single crystal photodetectors. 8–13…”

“…4 Sheng Wang et al reported that an UV photodetector based on BA 2 PbBr 4 (BA = CH 3 CH 2 CH 2 CH 2 NH 3 + ) single crystal film exhibited a detectivity of ∼10 12 Jones and a fast rise/decay response time of 9.7/8.8 ms. 5 Among the organic-inorganic hybrid perovskites, CH 3 NH 3 PbCl 3 perovskite single crystal is regarded as an attractive candidate for UV detection due to its large direct bandgap of ∼2.85 eV. 6–13 At present, some progress has been made in the research of CH 3 NH 3 PbCl 3 single crystal photodetectors. 8–13 For example, Hye Ri Jung et al reported that an Ag/TiO 2 /MAPbCl 3 /TiO 2 /Ag structured photodetector presented a responsivity of 0.004 A W −1 and a detectivity of 1.05 × 10 10 Jones at 430 nm under 2 V bias voltage.…”

“…6–13 At present, some progress has been made in the research of CH 3 NH 3 PbCl 3 single crystal photodetectors. 8–13 For example, Hye Ri Jung et al reported that an Ag/TiO 2 /MAPbCl 3 /TiO 2 /Ag structured photodetector presented a responsivity of 0.004 A W −1 and a detectivity of 1.05 × 10 10 Jones at 430 nm under 2 V bias voltage. 8 Jingda Zhao et al reported that a n−–n+ photo-diodes based on CH 3 NH 3 PbCl 3 single crystal exhibited a responsivity of 404.7 mA W −1 , and a detectivity of 4.87 × 10 11 Jones at 20V.…”

“…8–13 For example, Hye Ri Jung et al reported that an Ag/TiO 2 /MAPbCl 3 /TiO 2 /Ag structured photodetector presented a responsivity of 0.004 A W −1 and a detectivity of 1.05 × 10 10 Jones at 430 nm under 2 V bias voltage. 8 Jingda Zhao et al reported that a n−–n+ photo-diodes based on CH 3 NH 3 PbCl 3 single crystal exhibited a responsivity of 404.7 mA W −1 , and a detectivity of 4.87 × 10 11 Jones at 20V. 9 Giacomo Maculan et al reported that Pt/CH 3 NH 3 PbCl 3 single crystal/Ti/Au vertical structured visible-blind UV-photodetector was fabricated.…”