Innovative Surface Polarization Strategy Drives Inverted Perovskite Solar Cell Efficiency Above 26 Percent

Researchers use ACHCl molecules to passivate defects and induce surface polarization, pushing perovskite solar cell efficiency and stability to new heights.

By: AXL Media

Published: Apr 24, 2026, 6:34 AM EDT

Source: Information for this report was sourced from EurekAlert!

Overcoming the Interfacial Bottleneck

As inverted perovskite solar cells (PSCs) move toward large-scale commercialization, the industry faces a persistent challenge at the junction between the perovskite and the charge transport layer. These interfaces often suffer from carrier recombination and energy misalignment, which drain potential power. To address this, a research team led by Professors Jihuai Wu and Zhang Lan has introduced a surface polarization strategy. This method does not simply hide surface flaws but instead utilizes intrinsic defects, such as uncoordinated lead ions and halide vacancies, to anchor specialized molecules that improve the overall flow of electricity.

Synergistic Passivation with ACHCl Molecules

The core of this innovation lies in the introduction of 4-aminocyclohexanone hydrochloride, or ACHCl. This molecule features carbonyl groups that coordinate with lead ions while chloride ions fill the existing vacancies in the halide structure. This dual-action process effectively passivates defects, which would otherwise cause energy loss through non-radiative recombination. By neutralizing these traps, the researchers have created a more uniform surface that is better suited for high-speed electron extraction, a critical requirement for maximizing the performance of next-generation photovoltaic devices.

Creating a Functional Cationic Dipole Layer

A unique aspect of the ACHCl treatment is the formation of an ordered cationic dipole layer on the perovskite surface. The ACH+ cations anchor perpendicularly to the material, orienting their positively charged groups outward. This specific arrangement induces surface polarization, which results in a downward bending of the energy bands. This physical shift reduces the barrier that electrons must cross to reach the PCBM interface while simultaneously creating a block for holes. The result is a more efficient and directed movement of charges, which directly contributes to the device's record-breaking power output.