Light-trapping properties of the Si inclined nanowire arrays

Zhangyang

2021

Energy Tech

The structural design of excellent absorption and electron collection is the main challenge of the nanowire array (NWA) photocathode. Herein, the light trapping and photoemission performance of GaN and graded compositional AlGaN‐inclined NWA are systematically researched. The finite‐difference time domain method (FDTD) is used to calculate the light absorption under different inclined angles and array spacings. The results show that the NWA with an inclined angle of 0.4°–0.6° has greater light‐trapping capacity, which obtains up to 97% light absorption at a wavelength of 267 nm. The inclined graded compositional AlGaN NWA with a built‐in electric field has better photoemission performance. The external electric field further improves the electron collection capacity of the NWA cathode. The inclined AlGaN NWA cathode with the best parameters θ = 0.6°, L = 180 nm, and Eout = 2 V μm−1 obtains a quantum efficiency of 47.57% and collection efficiency of 31.09%. The study of the inclined graded compositional AlGaN NWA cathode assisted by the electric field provides an effective method for further utilization of incident light and emitted electrons.

Section: Introductionmentioning

confidence: 99%

Enhancement of Electron Collection and Light Trapping of Inclined GaN and AlGaN Nanowire Arrays

Zhangyang

2021

Energy Tech

“…Recently, some new strategies have been implemented to improve the lightharvesting capability of the NWs based on the symmetry breaking. For example, front (or rear)opening crescent design [33,34], off-axial core-shell design [35,36], asymmetrical nanovoid design [20], partially capped design [37][38][39][40], nanocone design [41][42][43][44], inclined design [45][46][47], disorder design [48][49][50][51][52] and crescent nanohole design [53]. More recently, we investigated the symmetry structure from circular NWs to elliptical NWs [54].…”

Section: Introductionmentioning

confidence: 99%

Enhanced Light-Harvesting in Single Rectangular Silicon Nanowires

Journal of Nanoelectronics and Optoelectronics

Lio

Wang

et al. 2021

Light-harvesting of single nanowires is very crucial to enhance conversion efficency of solar cells. Here, we systematically examined light-harvesting of single rectangular nanowires and found that light-harvesting of rectangular nanowires is increased contrasted with that of square nanowires, which is because decreasing the horizontal side can strengthen the leaky mode resonances and increasing the vertical side can increase the length of the light path. Numerical results showed that the photocurrent of single rectangular silicon nanowires is dramatically enhanced by 82.9% or 276.5% in comparison with that of square nanowires with the same vertical side (1000 nm) or horizontal side (100 nm), respectively. This work indicates that light-harvesting of single nanowires can be improved by decreasing the symmetry from the square to rectangular nanowires.

“…In recent years, there are many studies about the optical properties of various of nanostructures, such as nanowire (Garnett and Yang 2008, Garnett and Yang 2010, Cao et al 2010, Wu et al 2017, Xu et al 2017, Wang et al, 2017a, nanocone (Xu et al 2016), nano-hemisphere (Kang and Fang 2014), truncated nanocone (Kim et al 2018), pyramid (Tan et al 2017), motheye (Makableh et al 2018), nanohole (Han and Chen 2010, Peng et al 2010, Adib et al 2012, Chen et al 2014, Hong et al 2014, Wang et al 2017a, 2017b, Deng et al 2018, Fu et al 2018, and nano-conehole (Du et al 2011). The main materials of those nanostructures are silicon, silicon nitride, silicon carbide, gallium arsenide, or gallium nitride.…”

Section: Introductionmentioning

confidence: 99%

Comparative analysis of light trapping GaN nanohole and nanorod arrays for UV detectors

Zhangyang

et al. 2020

J Nanopart Res

In this paper, based on the excellent light trapping performance of the nanostructure, the structure of the electron emission layer of the ultraviolet detector is optimized. In this paper, simulation models of gallium nitride (GaN) nanohole arrays and nanorod arrays are designed by COMSOL Multiphysics software, which is based on the finite element method (FEM). In order to optimize the geometric parameters of GaN nanohole and nanorod arrays, and understand the influence of polarized light on them, the light absorption performance in the ultraviolet (UV) band has been fully analyzed. We found that when the lattice constant ranges from 200 to 500 nm, the GaN nanohole array and the GaN nanorod array have extreme absorptivity. And when the incident light has an inclination of 20°, the light trapping performance of the nanohole array can be further improved. GaN nanostructures with high light trapping capabilities will help improve the photoelectric emission efficiency of GaN photocathode and provide design reference for UV detectors with excellent performance.