Optimization of CuIn1-XGaXS2 Nanoparticles and Their Application in the Hole-Transporting Layer of Highly Efficient and Stable Mixed-Halide Perovskite Solar Cells

Khorasani, A ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1021/acsami.9b08714
  3. Publisher: American Chemical Society , 2019
  4. Abstract:
  5. Inorganic hole-transport materials (HTMs) have been frequently applied in perovskite solar cells (PSCs) and are a promising solution to improve the poor stability of PSCs. In this study, we investigate solution-processed copper indium gallium disulfide (CIGS) nanocrystals (NCs) as a dopant-free inorganic HTM in n-i-p type PSCs. Moreover, Cs0.05(MA0.17-FA0.83)0.95Pb(I0.83Br0.17)3 mixed-halide perovskite with proper crystalline quality and long-time stability was utilized as the light-absorbing layer under ambient conditions. To optimize the cell performance and better charge extraction from the perovskite layer, the Ga concentration in the Cu(In1-XGaX)S2 composition was changed, and the X value was altered between 0.0 and 0.75. It was shown that the CIGS band gap enhances with increasing Ga content; thus, with tunable band gaps and engineering of the energy level alignment, a better collection of photogenerated holes and a reduced electron-hole recombination rate could be achieved. The maximum power conversion efficiency of 15.6% was obtained for the PSC with Cu(In0.5Ga0.5)S2 hole-transport layer composition, which is the highest efficiency reported so far for CIGS-based dopant-free PSCs. This value is very close to the efficiency of devices fabricated with doped spiro-OMeTAD as an organic HTM. Additionally, the stability of nonencapsulated PSCs was studied, and CIGS-based devices demonstrated 70% retention after 90 days of aging in the dark and in 50% relative humidity conditions. This result is quite better than the similar measurements for the doped spiro-OMeTAD-based devices. © 2019 American Chemical Society
  6. Keywords:
  7. CIGS ; Energy conversion efficiency ; Hole transport layer ; Longtime stability ; Perovskite solar cell ; Conversion efficiency ; Copper compounds ; Energy conversion ; Energy gap ; Hole mobility ; Indium compounds ; Nanostructured materials ; Perovskite ; Perovskite solar cells ; Stability ; Sulfur compounds ; Electron hole recombination rate ; Energy level alignment ; Hole transport layers ; Hole transport materials ; Hole transporting layers ; Long-time stabilities ; Photogenerated holes ; Gallium compounds
  8. Source: ACS Applied Materials and Interfaces ; Volume 11, Issue 34 , 2019 , Pages 30838-30845 ; 19448244 (ISSN)
  9. URL: https://pubs.acs.org/doi/10.1021/acsami.9b08714