Aluminum oxide n Si field effect inversion layer solar cells with organic top contact

TL;DR

This paper introduces a novel solar cell design utilizing fixed negative charges at the Al2O3/n-Si interface to create a strong inversion layer, combined with an organic top contact to enhance voltage and efficiency.

Contribution

It presents a new photovoltaic device concept that leverages electrostatic inversion and organic contacts to improve n-Si solar cell performance.

Findings

Built-in voltages up to 755 mV achieved.

Open-circuit voltages up to 550 mV demonstrated.

Effective removal of Fermi level pinning with organic contact.

Abstract

We demonstrate a novel type of solar cell, one that uses fixed negative charges, formed at the interface of n-Si with Al2O3, to generate strong inversion at the Si surface by electrostatic repulsion. Built-in voltages of up to 755 mV are found at this interface. To be able to harness this large built-in voltage, we demonstrate a new photovoltaic device concept, where the photocurrent, generated in this inversion layer, is extracted via an inversion layer induced by a high work function PEDOT:PSS top contact, deposited on top of a passivating and dipole-inducing molecular monolayer. Results of the effect of the molecular monolayer on device performance yield open-circuit voltages of up to 550 mV for moderately doped Si, demonstrating the effectiveness of this contact structure in removing the Fermi level pinning that has hindered past efforts in developing this type of solar cell with n-type Si.