Engineering topics

Luo, Deying

Publications and source records attributed to Luo, Deying.

2 records

DOE OSTI2025

Boosting Tin Perovskite Solar Cell Performance via Light-Induced Interface Doping

Continuous breakthroughs have been achieved in the photoelectric conversion efficiency (PCE) of tin-based perovskite solar cells (TPSCs) in recent years. Inspired by performance improvements observed during device storage, we identified beneficial light-induced interface doping (LIID) in the TPSCs. In situ analyses using X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy reveal that ion migration and oxidation at the interface induce beneficial doping effects, enhancing carrier transport and significantly boosting device performance. By implementing specific illumination techniques or maximum power point tracking (MPPT) methods to achieve LIID, we increased the open-circuit voltage while maintaining a high short-circuit current, reaching a PCE of up to 14.91%. Furthermore, this efficiency was sustained at 70% of its maximum value after nearly 900 h of continuous operation. Our study introduces a novel approach to addressing energy band mismatch, paving the way for improved efficiency in tin-based perovskite solar cells.

Sun, Mulin↗

DOE OSTI2024

Diamine chelates for increased stability in mixed Sn–Pb and all-perovskite tandem solar cells

Perovskite tandem solar cells show promising performance but non-radiative recombination and its progressive worsening with time, especially in the mixed Sn–Pb low-bandgap layer, limit performance and stability. Here, in this study, we find that mixed Sn–Pb perovskite thin films exhibit a compositional gradient, with an excess of Sn on the surface – and we show this gradient exacerbates oxidation and increases the recombination rate. We find that diamines preferentially chelate Sn atoms, removing them from the film surface and achieving a more balanced Sn:Pb stoichiometry, making the surface of the film resistive to the oxidation of Sn. The process forms an electrically resistive low-dimensional barrier layer, passivating defects and reducing interface recombination. Further improving the homogeneity of the barrier layer using 1,2-diaminopropane results in more uniform distribution and passivation. Tandems achieve a power conversion efficiency of 28.8%. As a result, encapsulated tandems retain 90% of initial efficiency following 1000 hours of operating at the maximum power point under simulated one-sun illumination in air without cooling.

14 SOLAR ENERGY↗