Ultrasensitive Self‐Powered Solar‐Blind Deep‐Ultraviolet Photodetector Based on All‐Solid‐State Polyaniline/MgZnO Bilayer

Abstract

A high sensitivity self-powered solar-blind photodetector is successfully constructed based on the polyaniline/MgZnO bilayer. The maximum responsivity of the photodetector is 160 μA W at 250 nm under 0 V bias. The device also exhibits a high on/off ratio of ≈10 under 250 nm illumination at a relatively weak light intensity of 130 μW cm without any power.

Novel BeZnO Based Self‐Powered Dual‐Color UV Photodetector Realized via a One‐Step Fabrication Method

“…The result reveals that the photodetector exhibits self‐powered characteristics. Detectivity D* is the key figure of merits for weak signal detection and is defined as: where q is unit charge. Due to the extremely low dark current, the detectivity of the device is calculated as high as 1×10 9 Jones (330 nm) and 1.6×10 9 Jones (240 nm) under −2 V. Figure (b) shows the response spectra of the device under different bias and Figure (c) reveals the corrresponding peak responsivities at 240 nm and 330 nm as a function of operating voltage.…”

“…This can be owing to two main reasons: 1, due to the different crystal structures of MgO (cubic) and ZnO (wurtzite), the crystal quality of MgZnO deteriorates rapidly with the increase of Mg content and phase segregation occurs when Mg concentration is larger 33%; 2, high quality and stable p ‐ZnO or p ‐MgZnO which are required for realizing p‐n homojunctions are rather difficult to be prepared. Alternately, researchers fabricated a self‐powered UV photodetector based on hybrid inorganic/organic PANI/MgZnO heterojuction and a high on/off ratio (∼10 4 ) was achieved even under a relatively weak UV radiation . Nevertheless, up to present, self‐powered MgZnO based Schottky type UV photodetectors are rarely reported.…”

Enhanced Performance of a Self‐Powered Organic/Inorganic Photodetector by Pyro‐Phototronic and Piezo‐Phototronic Effects

“…In recent years, self-powered PDs have been demonstrated through integrating the PDs with external power sources such as piezoelectric and/or triboelectric nanogenerators to realize a self-powered photodetection system. [16][17][18][19][20] Compared to the integration of PDs with external power sources, the photovoltaic effect is a phenomenon naturally existed in semiconductor junction-based devices, [21] making the self-powered PDs facile-manufactured and cost-effective.Current photodetection technologies primarily rely on separate photoconductive semiconductor materials with certain band gaps corresponding to distinct spectral ranges, such as silicon for infrared light, [10,22,23] low band gap 2D semiconductors for visible light, [24][25][26] and gallium nitride (GaN) and zinc oxide (ZnO) for ultraviolet (UV) light. [16][17][18][19][20] Compared to the integration of PDs with external power sources, the photovoltaic effect is a phenomenon naturally existed in semiconductor junction-based devices, [21] making the self-powered PDs facile-manufactured and cost-effective.…”

High-sensitive and fast response to 255 nm deep-UV light of CH 3 NH 3 PbX 3 (X = Cl, Br, I) bulk crystals

“…As seen from figure 3 i , under illumination of 1.5 mW cm −2 255 nm light, the responsivities are 450 mA W −1 for CH 3 NH 3 PbCl 3 , 300 mA W −1 for CH 3 NH 3 PbBr 3 , and 120 mA W −1 for CH 3 NH 3 PbI 3 , respectively. As summarized in table 1, these results are 10 1 –10 3 times larger than previously reported wide bandgap semiconductors based deep-UV detectors such as Al x Ga 1− x N (34 mA W −1 ) [8], Mg x Zn 1− x O (0.1 mA W −1 ) [9], LaAlO 3 (72 mA W −1 ) [43], Ga 2 O 3 (0.32 mA W −1 ) [39], SrRuO 3 /BaTiO 3 /ZnO [40], ZnO-Ga 2 O 3 (9.7 mA W −1 ) [41] and MgZnO (0.16 mA W −1 ) [42]. As another determinant of detector performance, external quantum efficiency (EQE) is defined as the number of generated electrons per incident photon.…”