Creating high-performance, indoor solar cells with precise crystallization control

Flexible perovskite solar cells (FPSCs) are low-cost, lightweight, and can operate efficiently under indoor lighting, making them a prime candidate for commercial devices like wearable electronics and smart sensors.

The transition from conventional rigid device configurations to flexible manufacturing of perovskite solar cells presents substantial challenges in terms of device efficiency and stability. Therefore, Ma et al. developed a ligand-assisted crystallization strategy to enhance the crystalline quality of perovskite layers and synergistically optimize the photovoltaic performance of FPSCs.

“The low-temperature, flexible preparation process [of FPSCs] complicates high-quality perovskite film deposition,” said Zhao.

To solve this, the researchers leveraged the ammonium salt, 1,1,3,3-tetramethylguanidine hydrochloride (TMG), to modulate the crystallization kinetics of perovskite.

“By correlating crystalline quality with structural integrity and photovoltaic metrics in FPSCs, we demonstrated that precise nucleation window and crystallization duration control are essential for depositing mechanically stable, high-quality perovskite films, offering insights for future research,” said Zhao.

They achieved a power conversion efficiency (PCE) of 42.8% under 1000 lux white LED illumination, which is close to the light from indoor environments or the sun on an overcast day. After 200 hours at the same illumination condition, FPSCs maintained over 80% of their initial PCEs.

While FPSCs are feasible for Internet-of-Things devices and low-power sensors, the authors plan to use their methodology to build more stable FPSCs for extended integration uses.

“Currently, growing research attention has focused on the space applications of lightweight FPSCs, including spacecrafts and their accessories, due to their high power-to-weight ratio and radiation resistance,” Zhao said.

Source: “Guanidinium-mediated crystallization modulation for high-performance indoor flexible perovskite solar cells,” by Cheng Ma, Tianqi Niu, Xin Chen, Yang Yang, Shuang Wang, Zheng Zhang, Yongchao Tu, Chenqing Tian, Xuan Ji, Funan Sun, and Kui Zhao, Applied Physics Letters (2025). The article can be accessed at https://doi.org/10.1063/5.0278297 .

This paper is part of the High-Performance Thin-Film Indoor Photovoltaics Collection, learn more here .