A facile light‐trapping approach for ultrathin GaAs solar cells using wet chemical etching

• DOI: 10.1002/pip.3220
• Publication Date: 2019-12-19T03:08:18Z
• Authors: Maarten van Eerden; Gerard J. Bauhuis; Peter Mulder; Natasha Gruginskie; Marco Passoni; Lucio C. Andreani; Elias Vlieg; John J. Schermer
• Keywords: Ohmic contact; Isotropic etching

Abstract Thinning down the absorber layer of GaAs solar cells can reduce their cost and improve radiation hardness, which is important for space applications. However, lighttrapping schemes necessary to achieve high absorptance in these be experimentally challenging or introduce various parasitic losses. In this work, a facile light‐trapping approach based on wet chemical etching demonstrated. The rear‐side contact ultrathin wet‐chemically textured between local Ohmic points using an NaOH‐based etchant. resulting morphology characterized atomic force microscopy scanning electron miscroscopy. High broadband diffuse reflectance haze factors are measured bare Ag‐coated layers. successfully integrated as diffusive rear mirror thin‐film comprising 300‐nm Ag contact. Consistent increases short‐circuit current density ( J SC ) approximately 3 mA cm −2 (15%) achieved cells, while open‐circuit voltages fill do not suffer from mirror. best cell achieves 24.8 power conversion efficiency 21.4%. enhances outcoupling luminescence at open circuit, leading strong increase external luminescent efficiency.