Emitter thickness optimization for GaSb thermophotovoltaic cells grown by molecular beam epitaxy

GaSb thermophotovoltaic (TPV) devices were fabricated using a Molecular Beam Epitaxy (MBE) technique. Different emitter thicknesses (d e ) were studied to maximize the TPV cell’s short circuit current density. In this regard, the fabricated TPV device’s emitter was incrementally wet-etched and characterized to find the optimal thickness value. Simulations were performed using the Crosslight APSYS® platform over the full-spectrum range in order to predict device performance for different designs, while maximizing the photocurrent generation and enhancing the emitter sheet resistance. TPV devices were characterized electrically and optically. These experimental data showed that the etched emitter has minimal impact on the measured short circuit current density (J sc ) while simulated results demonstrated an optimal d e of 200 nm. Keywords: Large-area GaSb Thermophotovoltaic (TPV) Devices, Emitter Thickness, Short Circuit Current Density, Optimization, Carrier Lifetime. 1. INTRODUCTION