1D ZnSSe‐ZnSe Axial Heterostructure and its Application for Photodetectors

Abstract

possessing high photocurrent gain, fast response speed, high photosensitivity, wide response wavelength, and multiband photodetection are highly desired. [1][2][3][4] For this purpose, nanowires with large surface-to-volume ratio and quantum confinement effect show huge advantages over the bulk and thin film counterparts for fabrication of high performance photodetectors. [5][6][7][8][9][10] Since the discovery of carbon nanotubes, there are many reports about the photodetectors based on various 1D inorganic semiconductor nanostructures. For example, Si, Ge, ZnO, Ga 2 O 3 , CdS, ZnSe, CdSe, GaN, GaAs, InAs, CsPbBr 3 , and CsPb 2 Br 5 nanowires/nanobelts were used to fabricate photodetectors and demonstrate excellent photoresponse properties. [11][12][13][14][15][16] However, it is still very challenging to obtain the broad spectral response and high responsivity in these single component nanowire photodetectors due to the constraint of bandgap engineering, light absorptivity, and photogenerated carriers transfer efficiency. [17,18] High-quality semiconductor heterostructure nanowires (HNWs) integration with multicomponent can increase the absorption ability and extend the photoresponse range effectively. Actually, CdS/CdS x Se 1−x axial heterostructure nanowire photodetectors have shown more superior photodetection properties than that of single component CdS or CdS x Se 1−x . However, the controllable synthesis of axial HNWs is elusive and there are only few reports to date. [19,20] Different from the recent CdS/CdS x Se 1−x axial HNWs, which contain heavy-metal Cd element and might be unfavorable for practical application. ZnSe and ZnS with direct bandgap of 2.7 and 3.6 eV at room temperature are promising semiconductor materials for optoelectronics application in the visible and ultraviolet region. [21][22][23] Compared to binary ZnSe and ZnS nanowires, the recent synthesis and optical properties characterization of ZnS x Se 1−x ternary alloy nanostructures demonstrate tunable bandgap and photoluminescence (PL) properties, [24,25] which are similar to CdS x Se 1−x . These results favor the synthesis of ZnS x Se 1−x /ZnSe HNWs that is more friendly to environment and human health. However, to the best of our knowledge, there is not any report about the ZnSe x S 1−x /ZnSe axial heterostructure due to the phase structure, lattice mismatch, and the melting point between ZnSe and ZnS, which makes the epitaxial growth of ZnSe along the Semiconductor heterostructure nanowires (HNWs) are excellent candidates for application in compact optoelectronics devices with high performance due to the heterojunction interface effect. However, the controllable fabrication of high-quality nano-heterostructures is elusive. In this paper, the controllable growth and optoelectronics device application of high-quality ZnS 0.49 Se 0.51 / ZnSe axial HNWs are reported. The as-synthesized HNWs are straight with uniform diameter distribution of 50-100 nm. Microstructural characterization reveals single crystal and abrupt heterojunction int...

Progress in ultraviolet photodetectors based on II–VI group compound semiconductors

“…In 2019, Mu et al reported the development of a photodetector by using high-quality ZnS 0.49 Se 0.51 /ZnSe axial heterojunction nanowires (HNWs) with a uniform diameter distribution of 50-100 nm. 10 The axial ZnS 0.49 Se 0.51 /ZnSe HNWs were synthesized using an improved two-step CVD strategy. It is found that the axial ZnS 0.49 Se 0.51 /ZnSe HNW based photodetector exhibits a wide photoresponse range of 360-480 nm (Fig.…”

“…have been widely used for the fabrication of UVPDs in recent years due to their large bandgap, high exciton binding energy and exciton gain, good optical properties, and excellent thermal and environmental stabilities. [7][8][9][10] In addition, II-VI group semiconductors have higher electron and hole mobilities than those of other semiconductor materials with a similar bandgap. 11 Another important property is the direct band structure of II-VI group semiconductors, which determines the interband radiative recombination of electrons and holes, and the high efficiency of electron-hole pair generation after the absorption of photons.…”

“…This review is primarily focused on UVPDs based on II-VI group semiconductors. The device geometry based on II-VI group semiconductors mainly includes photo-conductive type, 19,[43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] heterojunctions, 10,52,[58][59][60][61][62] and phototransistors [62][63][64] (Fig. 2).…”

Influence of Annealing Temperature Modulation on the Structural and Optical Properties of ZnSe Thin Films

“…[11][12][13] In terms of basic optical properties, ZnSe can used in solar cells, protective and antireflection coating, blue laser diodes, light-emitting diodes, photodetector, and sensors. [14][15][16][17][18][19][20][21][22] With the rapid development of lasers, traditional linear optical devices have not been able to meet some specific requirements of high power laser and military fields. Therefore, nonlinear optical absorption (NOA) behaviors of chalcogenide thin films gradually attracted much attention of the researchers.…”

First-principles study of phase transition, elastic and thermodynamic properties of ZnSe at high pressure

“…ZnSe, a significant member of the II-VI semiconductor compounds, which is a light yellow solid compound with a band gap of 2.70 eV 8 . It is an excellent candidate for fabrication of visual displays and photodetectors, etc [9][10][11][12] . It is an essential prerequisite for material's synthesis and application to investigate the fundamental physical properties of ZnSe.…”