Abstract
Inorganic-organic halide organometal perovskites have demonstrated very promising performance for opto-electronic applications, such as solar cells, light-emitting diodes, lasers, single-photon sources, etc. However, the little knowledge on the underlying photophysics, especially on a microscopic scale, hampers the further improvement of devices based on this material. In this communication, correlated conventional photoluminescence (PL) characterization and wide-field PL imaging as a function of time are employed to investigate the spatially- and temporally-resolved PL in CH3NH3PbI3−xClx perovskite films. Along with a continuous increase of the PL intensity during light soaking, we also observe PL blinking or PL intermittency behavior in individual grains of these films. Combined with significant suppression of PL blinking in perovskite films coated with a phenyl-C61-butyric acid methyl ester (PCBM) layer, it suggests that this PL intermittency is attributed to Auger recombination induced by photoionized defects/traps or mobile ions within grains. These defects/traps are detrimental for light conversion and can be effectively passivated by the PCBM layer. This finding paves the way to provide a guideline on the further improvement of perovskite opto-electronic devices.
Highlights
Together with the unprecedented development of solution-processed inorganic-organic halide organometal perovskite-based solar cells (e.g., CH3 NH3 PbI3−x Clx and CH3 NH3 PbI3 ), with power conversion efficiency (PCE) evolving from 3.8% [1] to 20.1% [2], the characterization of these materials has made significant breakthroughs in the last few years [3]
Films, which are investigated in this communication, are prepared are prepared by spin-coating of a mixed halide precursor solution
We carry out steady-state photoluminescence in quantum excitation intensity regime, Photoluminescence quantum efficiency (PLQE) rises with the laser intensity
Summary
Together with the unprecedented development of solution-processed inorganic-organic halide organometal perovskite-based solar cells (e.g., CH3 NH3 PbI3−x Clx and CH3 NH3 PbI3 ), with power conversion efficiency (PCE) evolving from 3.8% [1] to 20.1% [2], the characterization of these materials has made significant breakthroughs in the last few years [3]. A number of different methods are employed, ranging from crystallographic study [4,5], photo-physical investigation [6,7,8], to electrical characterization [9,10], etc Both scientific and technical interests concentrate on how to further improve PCE and decrease the energy loss during the light conversion process. PLgeneral, characteristics of perovskite films are closely are closely with connected within itsterms quality, in terms the charge carrier lifetime and the recombination connected its quality, of the chargeofcarrier lifetime and the recombination pathway [16]. Charge carrier recombination is considered is asconsidered a combination of (1) trap-/defect-assisted
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.