Dipole-field-assisted charge extraction in metal-perovskite-metal back-contact solar cells

TL;DR

This paper demonstrates a simple perovskite solar cell design that uses dipole fields from self-assembled monolayers to enhance charge extraction without traditional transport layers, achieving high voltages and currents.

Contribution

It introduces a novel back-contact perovskite solar cell architecture utilizing dipole-assisted charge extraction with self-assembled monolayers, eliminating the need for separate transport layers.

Findings

Photovoltages of ~600 mV achieved with SAM modifications.

Photocurrents up to 12.1 mA/cm2 under simulated sunlight.

Effective charge extraction despite large electrode spacing.

Abstract

Hybrid organic-inorganic halide perovskites are low-cost solution-processable solar cell materials with photovoltaic properties that rival those of crystalline silicon. The perovskite films are typically sandwiched between thin layers of hole and electron transport materials, which efficiently extract photogenerated charges. This affords high-energy conversion efficiencies but results in significant performance and fabrication challenges. Herein we present a simple charge transport layer-free perovskite solar cell (PSC), comprising only a perovskite layer with two interdigitated gold back-contacts. Charge extraction is achieved via self-assembled molecular monolayers (SAMs) and their associated dipole fields at the metal/perovskite interface. Photovoltages of approximately 600 mV generated by SAM-modified PSCs are equivalent to the built-in potential generated by individual dipole layers. Efficient charge extraction results in photocurrents of up to 12.1 mA/cm2 under simulated sunlight, despite a large electrode spacing.