We fabricate and characterize methylammonium lead halide perovskite film as a novel back contact to CdTe thin‐film solar cells. We apply ~0.75 μm perovskite film at the interface of CdCl2‐activated and Cu‐doped CdTe surface and complete the device with Au back contact. We use Cu/Au back contact as a reference to compare results with novel back contact. Our investigation shows that incorporation of thin layer of perovskite film before the back contact metal reduces back contact barrier effect and improves fill factor (FF) and open‐circuit voltage (VOC) of the solar cells. Our low temperature JV results prove that thin‐film perovskite is a very necessary component in CdTe solar cells to reduce back contact barrier, to minimize interface or surface recombination, to improve collection efficiencies, and to increase the efficiency of solar cells. Our best device shows 7% increase in VOCto 0.875 V and ~7% increase in FF with the highest FF of 81%, and solar cell's efficiency finally increases by 10% with the use of MAPb(I1‐xBrx)3as an interface layer.
New light is shed on the previously known perovskite material, Cs2Au2I6, as a potential active material for high‐efficiency thin‐film Pb‐free photovoltaic cells. First‐principles calculations demonstrate that Cs2Au2I6has an optimal band gap that is close to the Shockley–Queisser value. The band gap size is governed by intermediate band formation. Charge disproportionation on Au makes Cs2Au2I6a double‐perovskite material, although it is stoichiometrically a single perovskite. In contrast to most previously discussed double perovskites, Cs2Au2I6has a direct‐band‐gap feature, and optical simulation predicts that a very thin layer of active material is sufficient to achieve a high photoconversion efficiency using a polycrystalline film layer. The already confirmed synthesizability of this material, coupled with the state‐of‐the‐art multiscale simulations connecting from the material to the device, strongly suggests that Cs2Au2I6will serve as the active material in highly efficient, nontoxic, and thin‐film perovskite solar cells in the very near future.
more » « less- Award ID(s):
- 1719353
- NSF-PAR ID:
- 10051111
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 30
- Issue:
- 12
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Air‐stable p‐type SnF2:Cs2SnI6with a bandgap of 1.6 eV has been demonstrated as a promising material for Pb‐free halide perovskite solar cells. Crystalline Cs2SnI6phase is obtained with CsI, SnI2, and SnF2salts in gamma‐butyrolactone solvent, but not with dimethyl sulfoxide and
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