Issue 29, 2023

The effect of Al2O3 electrical shielding on MoS2 energy structure modulation in MoS2/p-Si heterojunction solar cells

Abstract

In this work, the authors utilize the electrical-shielding effect to change the electronic properties and energy structure of MoS2 for enhancing the photovoltaic performance of MoS2/p-Si solar cells. The ALD-Al2O3 thin film functions as a contact doping layer with MoS2 to control its electron distribution and Fermi level through intrinsic negative charges. It was found that the electron density and mobility of MoS2 both increased when Al2O3 was introduced. The Fermi level of the doped MoS2 upshifted toward its valence band, decreasing the work function to 3.92 eV and enlarging the MoS2/p-Si energy level splitting. After Al2O3 doping, the built-in field (Vbi) of the MoS2/p-Si junction enhanced significantly to 610 mV, and the diffusion mechanism dominates the carrier transport process here. Under the synergistic effects of surface passivation and n-type doping of Al2O3, the Vocs of MoS2/p-Si solar cells improved by āˆ¼26%. Besides, the lower reflectivity in the Al2O3/MoS2 window layer leads to light absorption enhancement in a short wavelength and Jsc increasement in solar cells. Finally, we obtain an optimized bulk-like MoS2-based solar cell with a conversion efficiency of 5.02% (Voc 302.5 mV, Jsc 33.29 mA cmāˆ’2, and FF 49.88%) by energy band engineering. The depth-UPS analysis and Cā€“V fitting results revealed the nature of improvement of MoS2/p-Si photovoltaic properties, where the electrons directionally transporting and accumulating in MoS2 under electric fields caused by Al2O3 mainly influence the energy band alignment and pā€“n junction behavior at the MoS2/Si interface.

Graphical abstract: The effect of Al2O3 electrical shielding on MoS2 energy structure modulation in MoS2/p-Si heterojunction solar cells

Supplementary files

Article information

Article type
Paper
Submitted
19 Feb 2023
Accepted
22 Jun 2023
First published
27 Jun 2023

J. Mater. Chem. C, 2023,11, 10004-10015

The effect of Al2O3 electrical shielding on MoS2 energy structure modulation in MoS2/p-Si heterojunction solar cells

Y. Zhang, Z. Li, P. Tong, L. Zhang, W. Yu and X. Liu, J. Mater. Chem. C, 2023, 11, 10004 DOI: 10.1039/D3TC00628J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements