Plasma-Deposited Multilayer GaP/Si p-i-n Structure for Tandem Silicon-Based Solar Cells

The possibility of creating an upper junction of multijunction III-V/Si solar cells based on GaP/Si superlattices (SL), grown using a combination of plasma-enhanced atomic-layer deposition (PEALD) and plasma-enhanced chemical vapor deposition (PECVD) technologies at a temperature not exceeding 400 degrees C, is shown. Structural and electrophysical studies of GaP/Si SL were performed and the photovoltaic properties of solar cells based on them were explored. The obtained GaP/Si SL epitaxially grown on the silicon substrate has a crystalline structure. According to the electrochemical capacitance-voltage (ECV) measurements, oscillations on the electron concentration profile were observed with a period corresponding to the thickness of the layers. The spectral dependence of the external quantum efficiency (EQE) shows the broadening of the sensitivity to the long-wavelength region for solar cells based on GaP/Si SL in comparison with p-i-n structures based on GaP. The obtained results open up the possibility of using GaP/Si SL to increase the spectral sensitivity of the upper junction in double-junction III-V/Si systems.

Automated summary

This study demonstrates the feasibility of creating an upper junction of multijunction III-V/Si solar cells using GaP/Si superlattices grown at temperatures not exceeding 400°C with a combination of PEALD and PECVD technologies. The results show that GaP/Si superlattices can enhance the spectral sensitivity of the upper junction in double-junction III-V/Si systems.