Origin of low electron–hole recombination rate in metal halide perovskites

2018 ◽  
Vol 11 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Francesco Ambrosio ◽  
Julia Wiktor ◽  
Filippo De Angelis ◽  
Alfredo Pasquarello
Keyword(s):  
Recombination Rate ◽  
Spatial Separation ◽  
Metal Halide ◽  
Electron Hole ◽  
Excitonic State ◽  
Halide Perovskites ◽  
Hole Recombination

Isodensity representation of the hole and the electron in the excitonic state of CH3NH3PbI3 showing spatial separation of the polaronic charges.

Suppressing the electron–hole recombination rate in hematite photoanode with a rapid cooling treatment

2017 ◽  
Vol 350 ◽  
pp. 48-55 ◽  
Author(s):  
Jingran Xiao ◽  
Huali Huang ◽  
Qiuyang Huang ◽  
Le Zhao ◽  
Xiang Li ◽  
...  
Keyword(s):  
Recombination Rate ◽  
Electron Hole ◽  
Rapid Cooling ◽  
Hole Recombination

scholarly journals Low-frequency lattice phonons in halide perovskites explain high defect tolerance toward electron-hole recombination

2020 ◽  
Vol 6 (7) ◽  
pp. eaaw7453 ◽  
Author(s):  
Weibin Chu ◽  
Qijing Zheng ◽  
Oleg V. Prezhdo ◽  
Jin Zhao ◽  
Wissam A. Saidi
Keyword(s):  
Low Cost ◽  
Low Frequency ◽  
Nonradiative Recombination ◽  
Defect Tolerance ◽  
Electron Hole ◽  
Surface Hopping ◽  
Recombination Processes ◽  
Halide Perovskites ◽  
Electron And Hole States ◽  
Hole Recombination

Low-cost solution-based synthesis of metal halide perovskites (MHPs) invariably introduces defects in the system, which could form Shockley-Read-Hall (SRH) electron-hole recombination centers detrimental to solar conversion efficiency. Here, we investigate the nonradiative recombination processes due to native point defects in methylammonium lead halide (MAPbI3) perovskites using ab initio nonadiabatic molecular dynamics within surface-hopping framework. Regardless of whether the defects introduce a shallow or deep band state, we find that charge recombination in MAPbI3 is not enhanced, contrary to predictions from SRH theory. We demonstrate that this strong tolerance against defects, and hence the breakdown of SRH, arises because the photogenerated carriers are only coupled with low-frequency phonons and electron and hole states overlap weakly. Both factors appreciably decrease the nonadiabatic coupling. We argue that the soft nature of the inorganic lattice with small bulk modulus is key for defect tolerance, and hence, the findings are general to other MHPs.

scholarly journals Synthesis, characterization and photocatalytic activity of mesoporous Na-doped TiO2 nano-powder prepared via a solvent-controlled non-aqueous sol–gel route

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 54053-54062 ◽  
Author(s):  
Inderjeet Singh ◽  
Balaji Birajdar
Keyword(s):  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Surface Area ◽  
Recombination Rate ◽  
Sol Gel ◽  
Electron Hole ◽  
Photo Catalytic Activity ◽  
Nano Powder ◽  
Hole Recombination ◽  
Enhanced Crystallinity

The superior photo-catalytic activity of mesoporous Na doped TiO2 attributed to the combined effect of electron–hole recombination rate, increased surface area and enhanced crystallinity.

Accumulation of Deep Traps at Grain Boundaries in Halide Perovskites

2019 ◽  
Author(s):  
Ji-Sang Park ◽  
Joaquín Calbo ◽  
Young-Kwang Jung ◽  
lucy whalley ◽  
Aron Walsh
Keyword(s):  
Grain Boundaries ◽  
Perovskite Solar Cells ◽  
Extended Defects ◽  
Trap States ◽  
Bulk Crystals ◽  
Recombination Rates ◽  
Electron Hole ◽  
Interstitial Defects ◽  
Halide Perovskites ◽  
Hole Recombination

<div> <div> <div> <p>The behaviour of grain boundaries in polycrystalline halide perovskite solar cells remains poorly understood. Whereas theoretical studies indicate that grain boundaries are not active for electron-hole recombination, there have been observations of higher non-radiative recombination rates involving these extended defects. We find that iodine interstitial defects, which have been established as a recombination center in bulk crystals, tend to segregate at planar defects in CsPbI3. First-principles calculations show that enhanced structural relaxation of the defects at grain boundaries results in increased stability (higher concentration) and deeper trap states (faster recombination). We show how the grain boundary can be partly passivated by halide mixing or extrinsic doping, which replaces or suppresses the formation of trap states close to the grain boundaries.<br></p> </div> </div> </div>

Ferroelastic domains drive charge separation and suppress electron–hole recombination in all-inorganic halide perovskites: time-domain ab initio analysis

2020 ◽  
Vol 5 (4) ◽  
pp. 683-690 ◽  
Author(s):  
Ran Shi ◽  
Zhaosheng Zhang ◽  
Wei-hai Fang ◽  
Run Long
Keyword(s):  
Ab Initio ◽  
Time Domain ◽  
Charge Separation ◽  
Charge Recombination ◽  
Electron Hole ◽  
Nonadiabatic Coupling ◽  
Halide Perovskites ◽  
Ferroelastic Domains ◽  
Hole Recombination

CsPbBr3 perovskites containing ferroelastic domains inhibit non-radiative charge recombination by facilitating charge separation and decreasing nonadiabatic coupling.

Synergic effects of upconversion nanoparticles NaYbF4:Ho3+ and ZrO2 enhanced the efficiency in hole-conductor-free perovskite solar cells

Nanoscale ◽  
2018 ◽  
Vol 10 (46) ◽  
pp. 22003-22011 ◽  
Author(s):  
Yanyan Li ◽  
Li Zhao ◽  
Meng Xiao ◽  
Yimin Huang ◽  
Binghai Dong ◽  
...  
Keyword(s):  
Solar Cells ◽  
Visible Light ◽  
Recombination Rate ◽  
Perovskite Solar Cells ◽  
Upconversion Nanoparticles ◽  
Electron Hole ◽  
Dual Functional ◽  
Nir Light ◽  
Hole Recombination

This design enabled the dual-functional effects, that is, the harvesting of NIR light and its conversion to visible light and the reduction of the electron–hole recombination rate.

Accumulation of Deep Traps at Grain Boundaries in Halide Perovskites

2019 ◽  
Author(s):  
Ji-Sang Park ◽  
Joaquín Calbo ◽  
Young-Kwang Jung ◽  
lucy whalley ◽  
Aron Walsh
Keyword(s):  
Grain Boundaries ◽  
Perovskite Solar Cells ◽  
Extended Defects ◽  
Trap States ◽  
Bulk Crystals ◽  
Recombination Rates ◽  
Electron Hole ◽  
Interstitial Defects ◽  
Halide Perovskites ◽  
Hole Recombination

<div> <div> <div> <p>The behaviour of grain boundaries in polycrystalline halide perovskite solar cells remains poorly understood. Whereas theoretical studies indicate that grain boundaries are not active for electron-hole recombination, there have been observations of higher non-radiative recombination rates involving these extended defects. We find that iodine interstitial defects, which have been established as a recombination center in bulk crystals, tend to segregate at planar defects in CsPbI3. First-principles calculations show that enhanced structural relaxation of the defects at grain boundaries results in increased stability (higher concentration) and deeper trap states (faster recombination). We show how the grain boundary can be partly passivated by halide mixing or extrinsic doping, which replaces or suppresses the formation of trap states close to the grain boundaries.<br></p> </div> </div> </div>

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