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RESEARCH PRODUCT
Effects of Frequency Dependence of the External Quantum Efficiency of Perovskite Solar Cells
Clara ArandaPablo P. BoixGermà Garcia-belmonteJuan A. AntaSandheep RavishankarJuan Bisquertsubject
Materials sciencemetal drawingPerovskite solar cell02 engineering and technology010402 general chemistry01 natural sciencesperovskite solar cellsGeneral Materials SciencePhysical and Theoretical ChemistrySpectroscopyperovskitePerovskite (structure)PhotocurrentResistive touchscreenbusiness.industry021001 nanoscience & nanotechnologyquantum theory0104 chemical sciencesefficiencysolar cellsOptical chopperOptoelectronicsQuantum efficiency0210 nano-technologybusinessCurrent densitydescription
Perovskite solar cells are known to show very long response time scales, on the order of milliseconds to seconds. This generates considerable doubt over the validity of the measured external quantum efficiency (EQE) and consequently the estimation of the short-circuit current density. We observe a variation as high as 10% in the values of the EQE of perovskite solar cells for different optical chopper frequencies between 10 and 500 Hz, indicating a need to establish well-defined protocols of EQE measurement. We also corroborate these values and obtain new insights regarding the working mechanisms of perovskite solar cells from intensity-modulated photocurrent spectroscopy measurements, identifying the evolution of the EQE over a range of frequencies, displaying a singular reduction at very low frequencies. This reduction in EQE is ascribed to additional resistive contributions hindering charge extraction in the perovskite solar cell at short-circuit conditions, which are delayed because of the concomitant large low-frequency capacitance.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-05-22 |