Solvent-mediated surface modification of electron transport layers for efficient PbS quantum dot solar cells

Journal of Materials Chemistry A. 2026. Vol. 14. No. 25. P. 15971–15983.

Zaman N., Li Y., Zheng T., Zhou J., Basit A., Tauqeer H. A., Tayea B. Z., Yousaf M. S., Luo S., Liang Z., Chen X., Gutsev L., Sarkar R., Vasenko A., Xu X.

Interface engineering plays a critical role in determining the performance of lead sulfide (PbS) colloidal quantum dot (CQD) solar cells. Defects and surface states at the PbS–electron transport layer (ETL) interface critically govern charge extraction and recombination processes. ZnMgO nanoparticles are widely employed as ETLs due to their high electron mobility and facile synthesis; however, excess surface hydroxyl (–OH) groups introduce interfacial trap states that impede efficient electron extraction. In the present work, we have overcome these limitations through solvent-mediated passivation engineering of ZnMgO surfaces, which utilizes a simple toluene treatment. Untreated ZnMgO films have high surface energies and low wettability, which results in a lack of uniform coverage of a PbS CQDs film; such poor interfaces lead to an undesirable increase in the rate of recombination. Toluene treatment is capable of removing surface hydroxyl groups, thus creating a coherent, smooth interface, validated by morphological analysis and further analyzed via DFT calculations. Such modification is shown to suppress trap-assisted recombination and promote efficient transfer of electrons, which leads to significant improvement in Voc, Jsc, and FF. As a result, treated devices attained a PCE that was 12 times better when compared to untreated devices. These findings offer a straightforward and powerful approach to streamline efficient ETL/CQDs interface engineering thus minimizing interfacial flaws and realizing the full potential of PbS CQDs solar cells in practical and high-efficiency photovoltaic applications.

Keywords: модификация поверхности, surface modification, solar cells, Теория функционала плотности, солнечные элементы, Density functional theory (DFT), Electron Transport Layer, Interface Engineering, Электронный транспортный слой, Разработка интерфейсов

Publication based on the results of: Разработка высокоэффективных и стабильных перовскитных солнечных элементов (2027)