TY - JOUR
T1 - Comparison of Recombination Dynamics in CH3NH3PbBr3 and CH3NH3PbI3 Perovskite Films
T2 - Influence of Exciton Binding Energy
AU - Yang, Ye
AU - Yang, Mengjin
AU - Li, Zhen
AU - Crisp, Ryan
AU - Zhu, Kai
AU - Beard, Matthew C.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/12/3
Y1 - 2015/12/3
N2 - Understanding carrier recombination in semiconductors is a critical component when developing practical applications. Here we measure and compare the monomolecular, bimolecular, and trimolecular (Auger) recombination rate constants of CH3NH3PbBr3 and CH3NH3PbI3. The monomolecular and bimolecular recombination rate constants for both samples are limited by trap-assisted recombination. The bimolecular recombination rate constant for CH3NH3PbBr3 is 3.3 times larger than that for CH3NH3PbI3 and both are in line with that found for radiative recombination in other direct-gap semiconductors. The Auger recombination rate constant is 4 times larger in lead-bromide-based perovskite compared with lead-iodide-based perovskite and does not follow the reduced Auger rate when the bandgap increases. The increased Auger recombination rate, which is enhanced by Coulomb interactions, can be ascribed to the larger exciton binding energy, ≈40 meV, in CH3NH3PbBr3 compared with ≈13 meV in CH3NH3PbI3.
AB - Understanding carrier recombination in semiconductors is a critical component when developing practical applications. Here we measure and compare the monomolecular, bimolecular, and trimolecular (Auger) recombination rate constants of CH3NH3PbBr3 and CH3NH3PbI3. The monomolecular and bimolecular recombination rate constants for both samples are limited by trap-assisted recombination. The bimolecular recombination rate constant for CH3NH3PbBr3 is 3.3 times larger than that for CH3NH3PbI3 and both are in line with that found for radiative recombination in other direct-gap semiconductors. The Auger recombination rate constant is 4 times larger in lead-bromide-based perovskite compared with lead-iodide-based perovskite and does not follow the reduced Auger rate when the bandgap increases. The increased Auger recombination rate, which is enhanced by Coulomb interactions, can be ascribed to the larger exciton binding energy, ≈40 meV, in CH3NH3PbBr3 compared with ≈13 meV in CH3NH3PbI3.
UR - http://www.scopus.com/inward/record.url?scp=84948952915&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.5b02290
DO - 10.1021/acs.jpclett.5b02290
M3 - 文章
C2 - 26551036
AN - SCOPUS:84948952915
SN - 1948-7185
VL - 6
SP - 4688
EP - 4692
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 23
ER -