skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Remnant PbI 2 , an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?

Authors:
; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1179634
Grant/Contract Number:
SC0001059
Resource Type:
Journal Article: Published Article
Journal Name:
APL Materials
Additional Journal Information:
Journal Volume: 2; Journal Issue: 9; Related Information: CHORUS Timestamp: 2016-12-29 16:53:48; Journal ID: ISSN 2166-532X
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Cao, Duyen H., Stoumpos, Constantinos C., Malliakas, Christos D., Katz, Michael J., Farha, Omar K., Hupp, Joseph T., and Kanatzidis, Mercouri G.. Remnant PbI 2 , an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?. United States: N. p., 2014. Web. doi:10.1063/1.4895038.
Cao, Duyen H., Stoumpos, Constantinos C., Malliakas, Christos D., Katz, Michael J., Farha, Omar K., Hupp, Joseph T., & Kanatzidis, Mercouri G.. Remnant PbI 2 , an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?. United States. doi:10.1063/1.4895038.
Cao, Duyen H., Stoumpos, Constantinos C., Malliakas, Christos D., Katz, Michael J., Farha, Omar K., Hupp, Joseph T., and Kanatzidis, Mercouri G.. Mon . "Remnant PbI 2 , an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?". United States. doi:10.1063/1.4895038.
@article{osti_1179634,
title = {Remnant PbI 2 , an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?},
author = {Cao, Duyen H. and Stoumpos, Constantinos C. and Malliakas, Christos D. and Katz, Michael J. and Farha, Omar K. and Hupp, Joseph T. and Kanatzidis, Mercouri G.},
abstractNote = {},
doi = {10.1063/1.4895038},
journal = {APL Materials},
number = 9,
volume = 2,
place = {United States},
year = {Mon Sep 01 00:00:00 EDT 2014},
month = {Mon Sep 01 00:00:00 EDT 2014}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4895038

Save / Share:
  • Perovskite-containing solar cells were fabricated in a two-step procedure in which PbI{sub 2} is deposited via spin-coating and subsequently converted to the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite by dipping in a solution of CH{sub 3}NH{sub 3}I. By varying the dipping time from 5 s to 2 h, we observe that the device performance shows an unexpectedly remarkable trend. At dipping times below 15 min the current density and voltage of the device are enhanced from 10.1 mA/cm{sup 2} and 933 mV (5 s) to 15.1 mA/cm{sup 2} and 1036 mV (15 min). However, upon further conversion, the current density decreasesmore » to 9.7 mA/cm{sup 2} and 846 mV after 2 h. Based on X-ray diffraction data, we determined that remnant PbI{sub 2} is always present in these devices. Work function and dark current measurements showed that the remnant PbI{sub 2} has a beneficial effect and acts as a blocking layer between the TiO{sub 2} semiconductor and the perovskite itself reducing the probability of back electron transfer (charge recombination). Furthermore, we find that increased dipping time leads to an increase in the size of perovskite crystals at the perovskite-hole-transporting material interface. Overall, approximately 15 min dipping time (∼2% unconverted PbI{sub 2}) is necessary for achieving optimal device efficiency.« less
  • In this work, we developed an innovative approach to self-grow single crystalline CH 3NH 3PbI 3 directly on polycrystalline FTO/TiO 2 substrate, with which n-i-p type of perovskite solar cells were fabricated. The single crystalline nature of CH 3NH 3PbI 3 has been confirmed by X-ray diffraction and high resolution transmission electron microscopy, and it is observed that they possess smaller optic band gap and longer carrier life time. Highly efficient charge extractions occur at the interface between electron collecting TiO 2 and photo-harvesting CH 3NH 3PbI 3, resulting in a maximum short-circuit current density of 24.40 mA/cm 2. Themore » champion cell possesses a photovoltaic conversion efficiency of 8.78%, and there are still substantial room for further improvement, making it promising for the perovskite solar cell applications.« less
  • We have demonstrated the performance of inverted CH{sub 3}NH{sub 3}PbI{sub 3} perovskite-based solar cells (SCs) with a room temperature (RT) sputtered ZnO electron transport layer by adding fullerene (C{sub 60}) interlayer. ZnO exhibits a better matched conduction band level with perovskite and Al work function and around energy offset of 2.2 eV between highest occupied molecular orbital level of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite and valance band level of ZnO. However, the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite layer will be damaged during direct RT sputtering deposition of ZnO. Therefore, the C{sub 60} interlayer having matched conduction band level with ZnO andmore » CH{sub 3}NH{sub 3}PbI{sub 3} perovskite added between the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite and RT sputtered ZnO layers for protection prevents sputtering damages on the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite layer. The short-circuit current density (J{sub SC}, 19.41 mA/cm{sup 2}) and open circuit voltage (V{sub OC}, 0.91 V) of the SCs with glass/ITO/poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS)/perovskite/C{sub 60}/RT sputtered ZnO/Al structure is higher than the J{sub SC} (16.23 mA/cm{sup 2}) and V{sub OC} (0.90 V) of the reference SC with glass/ITO/PEDOT:PSS/perovskite/C{sub 60}/bathocuproine (BCP)/Al structure. Although the SCs with the former structure has a lower fill factor (FF%) than the SCs with the latter structure, its conversion efficiency η% (10.93%) is higher than that (10.6%) of the latter.« less