Manipulating the Distributions of Na and Cd by Moisture‐Assisted Postdeposition Annealing for Efficient Kesterite Cu ₂ ZnSnS ₄ Solar Cells

Effectively incorporating alkali metals or alternative isovalent cations into Cu2ZnSnS4 (CZTS) is considered one of the most promising strategies for realizing a step-change improvement in photovoltaic device performance. Herein, we successfully manipulate local distribution Na and Cd by moisture-assisted post-deposition annealing (MAPDA) treatment combined with subsequent heterojunction heat treatment. The MAPDA facilitates controllable reduction concentration, thus promoting spontaneous diffusion region. A 150 °C low-temperature after enables further modification distributions, leading to significantly enhanced optoelectronic properties at CZTS/CdS greatly improved performance peak conversion efficiency 9.40 %. modified improves quasi-Fermi level splitting under low photon injection, making CZTS solar cells more feasible low-light applications. This work provides an effective approach simultaneously Cd, enabling pronounced quality boost efficiencies. Insights gleaned from this may also be applicable manipulating other critical trace elements chalcogenide materials general. article protected copyright. All rights reserved.