Work

Direct growth of tungsten disulfide on gallium nitride and the photovoltaic characteristics of the heterojunctions

Year: 2020

Type: article

Abstract: Photovoltaic device construct with a 2D nanomaterial atop a 3D wide bandgap semiconductor enables van Hove singularity induced enhanced light absorption on the front surface in close proximity (few atoms above) to the depletion region. Here, thin layers of tungsten disulfide (WS 2 ) varying from mono to few layers were grown directly on both n-gallium nitride (GaN) and p-GaN via low pressure chemical vapor deposition. The conditions for WS 2 growth were optimized for a larger coverage of the GaN substrate. The WS 2 film was characterized using confocal Raman spectroscopy and x-ray photoelectron spectroscopy. Ultraviolet photoelectron spectroscopy measurement was conducted to elucidate the electronic band structures of WS 2 on top of GaN. Afterwards, WS 2 /GaN heterojunction photovoltaic devices were fabricated. The current density–voltage ( J – V ) tests were conducted to illustrate the electrical performance. The device showed an open circuit voltage of 0.53 mV and a short circuit current density of 60 µ A cm −2 , 85% higher than that of a WS 2 /Si solar cell. An external quantum efficiency was measured to be near 60% for red and infrared, and above 50% in the violet region.

Source: Semiconductor Science and Technology

DOI: 10.1088/1361-6641/abd18f

Authors: Yu Wen, Rousan Debbarma, Md Golam Rasul, Reza Shahbazian-Yassar, Vikas Berry, Junxia Shi

Institution: University of Illinois Chicago

Language: English

Topic: 2D Materials and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: bronze