TY - JOUR
T1 - Quantifying Charge Carrier Recombination Losses in MAPbI3/C60 and MAPbI3/Spiro-OMeTAD with and without Bias Illumination
AU - Caselli, V. M.
AU - Savenije, T. J.
PY - 2022
Y1 - 2022
N2 - To increase the open-circuit voltage in perovskite-based solar cells, recombination processes at the interface with transport layers (TLs) should be identified and reduced. We investigated the charge carrier dynamics in bilayers of methylammonium lead iodide (MAPbI3) with C60 or Spiro-OMeTAD using time-resolved microwave conductance (TRMC) measurements with and without bias illumination (BI). By modeling the results, we quantified recombination losses in bare MAPbI3 and extraction into the TLs. Only under BI did we find that the density of deep traps increases in bare MAPbI3, substantially enhancing trap-mediated losses. This reversible process is prevented in a bilayer with C60 but not with Spiro-OMeTAD. While under BI extraction rates reduce significantly in both bilayers, only in MAPbI3/Spiro-OMeTAD does interfacial recombination also increases, substantially reducing the quasi Fermi level splitting. This work demonstrates the impact of BI on charge dynamics and shows that adjusting the Fermi level of TLs is imperative to reduce interfacial recombination losses.
AB - To increase the open-circuit voltage in perovskite-based solar cells, recombination processes at the interface with transport layers (TLs) should be identified and reduced. We investigated the charge carrier dynamics in bilayers of methylammonium lead iodide (MAPbI3) with C60 or Spiro-OMeTAD using time-resolved microwave conductance (TRMC) measurements with and without bias illumination (BI). By modeling the results, we quantified recombination losses in bare MAPbI3 and extraction into the TLs. Only under BI did we find that the density of deep traps increases in bare MAPbI3, substantially enhancing trap-mediated losses. This reversible process is prevented in a bilayer with C60 but not with Spiro-OMeTAD. While under BI extraction rates reduce significantly in both bilayers, only in MAPbI3/Spiro-OMeTAD does interfacial recombination also increases, substantially reducing the quasi Fermi level splitting. This work demonstrates the impact of BI on charge dynamics and shows that adjusting the Fermi level of TLs is imperative to reduce interfacial recombination losses.
UR - http://www.scopus.com/inward/record.url?scp=85136316357&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.2c01728
DO - 10.1021/acs.jpclett.2c01728
M3 - Article
AN - SCOPUS:85136316357
SN - 1948-7185
VL - 13
SP - 7523
EP - 7531
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 32
ER -