Enhanced performance of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/silicon solar cells employing inverted pyramidal silicon by one-step copper catalyzed etching

Abstract

Here, micro-inverted pyramid structured silicon (Si) surface is prepared via simple yet effective, low-cost one-step copper catalyzed chemical etching (CuCCE) for superior light trapping. The inverted pyramidal (IP) arrays are obtained on large area of the partial polished (PP) Si surface by CuCCE in etch bath consisting of Cu(NO3)2/HF/H2O2 at 50 °C. The IP-Si shows significantly reduced total surface reflectance (<7%) than the PP-Si (>30%) for broad spectral range. Hybrid solar cells (HSCs), having junction between poly(3,4-ethylenedioxy thiophene):poly(styrene sulfonate)(PEDOT:PSS) and n-Si, are demonstrated on the IP-Si and PP-Si surfaces; named as IP-SC and PP-SC respectively. Direct enhancement of ∼3 fold in efficiency is observed for IP-SC than the PP-SC. The improved performance is attributed to enhanced light trapping ability of the IP-Si leading to the improved short circuit current density of ∼32 mA/cm2, ∼1.3 times higher than the PP-SC. The HSCs on CuCCE IP-Si surface is presented as a ‘proof of concept’ for future high efficiency devices.