Programmable Charge Trap for Junction-less selective extraction of holes in Solar Cells

TL;DR

This paper introduces a novel programmable charge trap using an Oxide-Nitride-Oxide stack for selective hole extraction in solar cells, offering a new approach to improve efficiency and simplify device design.

Contribution

It proposes a new programmable charge trap for majority carrier extraction, enabling efficiency compensation and standalone hole selection in solar cells.

Findings

Charge trap can compensate for efficiency loss in various solar cell types.

Charge trap functions as a standalone hole selection scheme.

Simulation results demonstrate improved carrier selectivity and efficiency.

Abstract

Selective extraction of photo-generated carriers is a fundamental challenge in solar cells which is usually achieved through junctions with the associated doping as well as band offset differences. In this context, here we propose a new paradigm for selective extraction for majority carriers through novel usage of the programmable charge trap which comprises of Oxide-Nitride-Oxide (ONO) stack and has the primary function of holding electrically injected charge. Through detailed numerical simulations, here we show that such a charge trap with an additional metal contact can (i) compensate for efficiency loss due to sub-optimal passivation and sub-optimal hole selectivity in homojunction as well as transition metal oxide-based heterojunction solar cells and (ii) can also function as a standalone hole selection scheme. The proposed scheme, with its easy integration and the capability of programmable compensation of performance loss, is of interest to the photovoltaic community.