Highly Sensitive and Stable Self‐Powered UV Photodetector Based on Amorphous ZnGa₂O₄/NiO Type‐II p–n Heterojunction via Low‐Temperature and Band Alignment

Abstract

eV, tunable carrier concentration, and excellent structural and thermal stability, is considered an exceptional candidate material for fabricating highperformance solar-blind UV PDs. [9][10][11][12] Previous PDs based on ZnGa 2 O 4 crystals grown at high substrate temperatures (>700 °C) were mainly constructed using planar photoconductive PDs. [13,14] Although these have high photoelectric gain, their practical application is limited by the problem of slow reaction rate due to persistent photoconductive (PPC) behavior and the need for external power supply. [1,15,16] Moreover, it is extremely difficult to obtain high-quality ZnGa 2 O 4 single-crystal substrate, and high growth temperatures limit the development of ZnGa 2 O 4 in flexible devices in terms of scalability, portability, flexibility, and wearability. [17,18] In particular, amorphous ZnGa 2 O 4 PDs exhibit competitive response properties in solar-blind UV band. [13] The oxygen atmosphere affects the performance of amorphous ZnGa 2 O 4 in the low-temperature deposition process. [2]

Multifunctional solar‐blind ultraviolet photodetectors based on p‐PCDTBT/n‐Ga2O3 heterojunction with high photoresponse

“…Except for the PDCR, other response parameters show a decreasing trend as the light intensity increases monotonously. Such a decreased tendency is related to the self‐heating effects of the photodetector illuminated in high light intensity, which is also observed in other oxides‐based photodetectors 45,46 . The self‐heating effects could induce large photon‐electron scattering so that it could increase the possibility of electron–hole recombination.…”

“…Such a decreased tendency is related to the self-heating effects of the photodetector illuminated in high light intensity, which is also observed in other oxides-based photodetectors. 45,46 The self-heating effects could induce large photon-electron scattering so that it could increase the possibility of electron-hole recombination. It can be derived that the preferable R, D*, and EQE of the PCDTBT/a-Ga 2 O 3 -based photodetector are 187 A W -1 , 1.3 Â 10 16 Jones, and 9.1 Â 10 4 % under the incident light intensity of 11 μW cm -2 , respectively.…”

High-performance asymmetric electrode structured light-stimulated synaptic transistor for artificial neural networks

“…52 Furthermore, these two materials can form typical type-II band alignment, which is beneficial for trapping and storing charges. 53 Therefore, we selected DPP-DTT and N2200 for the heterostructure. The molecular structures of DPP-DTT and N2200 are shown in Fig.…”

Toward High-Performance Self-Powered Near-Ultraviolet Photodetection by Constructing a Unipolar Heterojunction

“…Nowadays, Si-based or GaSb-based devices have drawn enormous attentions in modern optoelectronic devices. − Particularly, Si-based photodetectors are compatible with mature microelectronics technology, which has been realized in mass production. At the same time, near-ultraviolet photodetectors are widely employed in ozone monitoring, solar radiation studies, atmospheric re-entry monitoring, environmental monitoring, national defense early warning, and so on. − However, due to the narrow-band-gap semiconductors and high reflection coefficient and shallow penetration depth of near-ultraviolet light, Si and GaSb are rarely employed for near-ultraviolet photodetection . Nowadays, many studies are attempting to adopt wide-band-gap semiconductor/Si heterojunction photodetectors to achieve ultraviolet photodetector. , Unfortunately, due to the visible light absorption and response of Si, the reported wide-band-gap semiconductor/Si heterojunction photodetectors exhibit poor ultraviolet selectivity, limiting the direct application in ultraviolet detection under a visible light background. − In this work, PbI 2 nanosheets are prepared directly on Si and GaSb wafers by a simple solution process to construct unipolar heterojunctions for near-ultraviolet photodetection.…”