Inverted GaInP/GaAs Three-Terminal Heterojunction Bipolar Transistor Solar Cell

TL;DR

This paper demonstrates an inverted GaInP/GaAs heterojunction bipolar transistor solar cell with improved performance, enabling new manufacturing techniques like substrate reuse and mechanical stacking for cost-effective high-efficiency solar technology.

Contribution

It introduces an inverted growth and processing method for three-terminal HBT solar cells, facilitating substrate reuse and potential low-cost high-efficiency III-V-on-Si integration.

Findings

Inverted processing is feasible for HBT solar cells.

Reduced shadow factor and series resistance improve performance.

Potential for substrate reuse and mechanical stacking.

Abstract

Here we present the experimental results of an inverted three-terminal heterojunction bipolar transistor solar cell (HBTSC) made of GaInP/GaAs. The inverted growth and processing enable contacting the intermediate layer (base) from the bottom, which improves the cell performance by reducing shadow factor and series resistance at the same time. With this prototype we show that an inverted processing of a three-terminal solar cell is feasible and pave the way for the application of epitaxial lift-off, substrate reuse and mechanical stacking to the HBTSC which can eventually lead to a low-cost high-efficiency III-V-on-Si HBTSC technology.