Related Experiment Video
Updated: Jul 12, 2026
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Coherent transformation of metal halide perovskites
Pinghui Yang1, Haokun Shi1, Zhen Wang1
1Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 210003, Jiangsu, China.
Abstract:
Metal-halide perovskites offer high optoelectronic performance but translating laboratory efficiencies into controllable, reproducible processes remains challenging. Perovskite crystallization is tracked by in situ multiwavelength absorption to show that coherent, layer-by-layer conversion of low-n intermediates to three-dimensional perovskite, quantified by a transformation index (TI), correlates with device quality. TI displays a Sabatier-type dependence on additive-precursor interaction strength and concentration, defining an engineering window for reproducible film formation. Within this window, post-treatment-free devices reach a champion power conversion efficiency of 26.40% with improved stability and reduced device scatter at laboratory scale. TI is extractable from an inline optical readout and provides a measurable metric for additive screening and process tuning. Its applicability to scalable deposition is further validated through slot-die coated mini-modules, offering a practical pathway for inline process control.
More Related Videos
Related Concept Videos
02:42Valence Bond Theory
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...