Quantum Dynamics of Photogenerated Charge Carriers in Hybrid Perovskites: Dopants, Grain Boundaries, Electric Order, and Other Realistic Aspects

Abstract

Dissipation of photon energy to heat and recombination of photogenerated charge carriers are among the main factors limiting the efficiency of solar-light-harvesting devices. The dynamics of excited electrons and holes depends critically on the microscopic structure of a material, including dopants, defects, grain boundaries, crystallinity, and electric order. This Perspective summarizes recent findings and suggests directions for improvement of hybrid organic−inorganic perovskite materials, established by means of nonadiabatic dynamics (NAMD) simulations. Combined with real-time time-dependent density functional theory, NAMD provides an ab initio description of the photoinitiated processes that occur far from thermodynamic equilibrium. It includes realistic aspects of the material's structure and gives unique atomistic insights into the photoactive material properties.

Excitations Partition into Two Distinct Populations in Bulk Perovskites

“…Perovskite thin films and nanocrystals have also been used in light‐emitting devices, including low‐threshold optically pumped lasers and bright photodiodes . The extraordinary potential of perovskites in optoelectronic applications has prompted extensive research into their material and electronic properties . Optical spectroscopic studies such as photoluminescence (PL) lifetime and transient absorption (TA) spectroscopy have been performed on perovskite thin films, revealing photogeneration of free charge carriers, bimolecular charge recombination dynamics, band filling behavior, and long carrier diffusion lengths .…”

P‐52: A Novel Six‐Mask Low‐Temperature Polycrystalline Silicon Architecture for TFT‐LCD Application

“…On the other hand, the grain size of poly-Si also affects Iphoto because photogenerated holes and electrons must pass through many grain boundaries of poly-Si to reach the electrodes. [9,10] The more grain boundaries will lead to the stronger barrier effect to carriers, and result in weaker Iphoto. Therefore, the grain size of poly-Si can also be adjusted to reduce the Iphoto.…”

Unraveling the Photogenerated Electron Localization on the Defect-Free CH3NH3PbI3(001) Surfaces: Understanding and Implications from a First-Principles Study

“…Consequently, one can suggest that the high photocatalytic and high photovoltaic performance of MAPbI3 perovskites may be attributed to their low electron-hole recombination rate and long excited-state lifetime 26 . Long, Prezhdo and co-workers reported that the charge recombination was sensitive to the grain boundaries and dopants, and the grain boundaries significantly enhanced the electron-hole coupling [27][28] . They also revealed that the localization of the electronic states can decrease electron-hole interactions and prolong the excited-state lifetime 29 .…”