Fabrication of GaAs photovoltaic cells with InAs-submonolayer quantum dots

• Grant number: 24/14111-3
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2025
• End date: January 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Alain André Quivy
• Grantee: Alain André Quivy
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In this project, we intend to optimize the growth conditions of InAs/GaAs submonolayer quantum dots (SMLQDs) formed in the presence of a (2´4) surface reconstruction at high temperature and arsenic flux to obtain nanostructures of better quality than in the literature. This will be done by modifying the large number of parameters involved in the deposition of SMLQDs and evaluating their influence on the optical properties of the nanostructures with photoluminescence measurements. Next, these SMLQDs will be inserted in the middle of the p-i-n junction of a GaAs solar cell, used as a reference in this study, thus obtaining an intermediate-band cell. The doping of the SMLQDs will be systematically varied to optimize the carrier population in the intermediate band. These devices will be characterized with a solar simulator and an external-quantum-efficiency experimental setup with the expectation that one of them will exceed the efficiency of the reference cell, thus demonstrating the possibility of overcoming the Shockley-Queisser limit with a single junction. (AU)