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The optoelectronic role of chlorine in CH3NH3PbI3(Cl)-based perovskite solar cells.

Chen Q, Zhou H, Fang Y, Stieg AZ, Song TB, Wang HH, Xu X, Liu Y, Lu S, You J, Sun P, McKay J, Goorsky MS, Yang Y - Nat Commun (2015)

Bottom Line: Specifically, chlorine incorporation has been shown to affect the morphological development of perovksite films, which results in improved optoelectronic characteristics for high efficiency.Here we report an effective strategy to investigate the role of the extrinsic ion in the context of optoelectronic properties, in which the morphological factors that closely correlate to device performance are mostly decoupled.The chlorine incorporation is found to mainly improve the carrier transport across the heterojunction interfaces, rather than within the perovskite crystals.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, USA [2] California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.

ABSTRACT
Perovskite photovoltaics offer a compelling combination of extremely low-cost, ease of processing and high device performance. The optoelectronic properties of the prototypical CH3NH3PbI3 can be further adjusted by introducing other extrinsic ions. Specifically, chlorine incorporation has been shown to affect the morphological development of perovksite films, which results in improved optoelectronic characteristics for high efficiency. However, it requires a deep understanding to the role of extrinsic halide, especially in the absence of unpredictable morphological influence during film growth. Here we report an effective strategy to investigate the role of the extrinsic ion in the context of optoelectronic properties, in which the morphological factors that closely correlate to device performance are mostly decoupled. The chlorine incorporation is found to mainly improve the carrier transport across the heterojunction interfaces, rather than within the perovskite crystals. Further optimization according this protocol leads to solar cells achieving power conversion efficiency of 17.91%.

No MeSH data available.


Related in: MedlinePlus

Defect and carrier behaviour of the perovskite devices.(a) Arrhenius plots of the inflection frequencies in the admittance spectra for devices based on Reference (squares) and Sample 1 (circles) determined from the derivative fdC/df. The value Ea is the activation energy for the traps, where Ea for Reference and Sample 1 is 74.4 and 21.6 meV, respectively. (b) Transient photovoltage decay curves and extracted lifetime of the injected carrier in the devices based on Reference (squares) and Sample 1 (circles). The charge lifetime in Sample 1 with chlorine incorporation was measured to be two times longer than that of Reference.
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f7: Defect and carrier behaviour of the perovskite devices.(a) Arrhenius plots of the inflection frequencies in the admittance spectra for devices based on Reference (squares) and Sample 1 (circles) determined from the derivative fdC/df. The value Ea is the activation energy for the traps, where Ea for Reference and Sample 1 is 74.4 and 21.6 meV, respectively. (b) Transient photovoltage decay curves and extracted lifetime of the injected carrier in the devices based on Reference (squares) and Sample 1 (circles). The charge lifetime in Sample 1 with chlorine incorporation was measured to be two times longer than that of Reference.

Mentions: We further investigate carrier recombination dynamics in the scope of the entire heterojunction across the device. Transient photovoltage decay was perfomed under open circuit condition with one sun illumination (See Supplementary Information). In this scenario, the carriers cannot be swiped out of the device but recombine, so transient photovoltage decay correlates to carrier recombination lifetimes in the working device46. The photovoltage decay curves for devices based on Sample 1 and Reference are plotted in Fig. 7. In both cases, the photovoltage decay constants are on the scale of microseconds, in accordance to the recent report9. The charge lifetime in the device with chlorine incorporation was measured to be two times longer than that of Reference. This indicates that carrier recombination along the entire device has been suppressed due to chlorine incorporation, which consequently improves the device efficiency. Since the perovskite film itself does not exhibit convincing evidence for significant reduction of the carrier recombination neither in the bulk nor along the GBs, it is expected that the improvement possibly originates from the interfaces between the perovskites and the relevant carrier transport layers due to the chlorine inclusion.


The optoelectronic role of chlorine in CH3NH3PbI3(Cl)-based perovskite solar cells.

Chen Q, Zhou H, Fang Y, Stieg AZ, Song TB, Wang HH, Xu X, Liu Y, Lu S, You J, Sun P, McKay J, Goorsky MS, Yang Y - Nat Commun (2015)

Defect and carrier behaviour of the perovskite devices.(a) Arrhenius plots of the inflection frequencies in the admittance spectra for devices based on Reference (squares) and Sample 1 (circles) determined from the derivative fdC/df. The value Ea is the activation energy for the traps, where Ea for Reference and Sample 1 is 74.4 and 21.6 meV, respectively. (b) Transient photovoltage decay curves and extracted lifetime of the injected carrier in the devices based on Reference (squares) and Sample 1 (circles). The charge lifetime in Sample 1 with chlorine incorporation was measured to be two times longer than that of Reference.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490385&req=5

f7: Defect and carrier behaviour of the perovskite devices.(a) Arrhenius plots of the inflection frequencies in the admittance spectra for devices based on Reference (squares) and Sample 1 (circles) determined from the derivative fdC/df. The value Ea is the activation energy for the traps, where Ea for Reference and Sample 1 is 74.4 and 21.6 meV, respectively. (b) Transient photovoltage decay curves and extracted lifetime of the injected carrier in the devices based on Reference (squares) and Sample 1 (circles). The charge lifetime in Sample 1 with chlorine incorporation was measured to be two times longer than that of Reference.
Mentions: We further investigate carrier recombination dynamics in the scope of the entire heterojunction across the device. Transient photovoltage decay was perfomed under open circuit condition with one sun illumination (See Supplementary Information). In this scenario, the carriers cannot be swiped out of the device but recombine, so transient photovoltage decay correlates to carrier recombination lifetimes in the working device46. The photovoltage decay curves for devices based on Sample 1 and Reference are plotted in Fig. 7. In both cases, the photovoltage decay constants are on the scale of microseconds, in accordance to the recent report9. The charge lifetime in the device with chlorine incorporation was measured to be two times longer than that of Reference. This indicates that carrier recombination along the entire device has been suppressed due to chlorine incorporation, which consequently improves the device efficiency. Since the perovskite film itself does not exhibit convincing evidence for significant reduction of the carrier recombination neither in the bulk nor along the GBs, it is expected that the improvement possibly originates from the interfaces between the perovskites and the relevant carrier transport layers due to the chlorine inclusion.

Bottom Line: Specifically, chlorine incorporation has been shown to affect the morphological development of perovksite films, which results in improved optoelectronic characteristics for high efficiency.Here we report an effective strategy to investigate the role of the extrinsic ion in the context of optoelectronic properties, in which the morphological factors that closely correlate to device performance are mostly decoupled.The chlorine incorporation is found to mainly improve the carrier transport across the heterojunction interfaces, rather than within the perovskite crystals.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, USA [2] California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.

ABSTRACT
Perovskite photovoltaics offer a compelling combination of extremely low-cost, ease of processing and high device performance. The optoelectronic properties of the prototypical CH3NH3PbI3 can be further adjusted by introducing other extrinsic ions. Specifically, chlorine incorporation has been shown to affect the morphological development of perovksite films, which results in improved optoelectronic characteristics for high efficiency. However, it requires a deep understanding to the role of extrinsic halide, especially in the absence of unpredictable morphological influence during film growth. Here we report an effective strategy to investigate the role of the extrinsic ion in the context of optoelectronic properties, in which the morphological factors that closely correlate to device performance are mostly decoupled. The chlorine incorporation is found to mainly improve the carrier transport across the heterojunction interfaces, rather than within the perovskite crystals. Further optimization according this protocol leads to solar cells achieving power conversion efficiency of 17.91%.

No MeSH data available.


Related in: MedlinePlus