2022 Chemical Engineering Journal : The highest efficiency of Ag3BiI6 rudorffite solar cells reaches 2.77%!
1. Photovoltaics of the lead-free absorber layer, Ag3BiI6 ,were obtained from the thermal assisted blade coating technique.
2. Modification of carrier transporting layers renders Ag3BiI6 to exhibit superior photovoltaic performance with 2.77%.
3. The champion device with a one-millimeter square active area can achieve 2.03%.
4. The devices can maintain 80% of initial PCE after 3,000 h stability tests in ambient without encapsulation.
Currently, high-efficiency perovskite solar cells mainly include lead-based light-absorbing layers. In recent years, perovskite solar, the unprecedented Power Conversion Efficiency (PCE) makes it an optimistic solution for sustainable or renewable energy. However, lead in perovskite solar cells, this toxic component and its stability in the surrounding environment have become topics of public discussion. Therefore, resolving these two issues is urgent for developing perovskite solar cells.
In August 2022, CEJ published a research result of a Ag3BiI6 rudorffite solar cell with a maximum PCE of 2.77%. Research team select Ag3BiI6 rudorffite as an active layer prepared by the thermal assisted doctor blade coating method to replace the conventional lead-based perovskite active layer. In this study, in order to align the energy levels between the carrier transport layer and the light absorption layer, the two carrier transport layers were doped. Increase the PCE of the doctor blade device from 2.06% to 2.77%. These devices store more than 3,000 unpackaged in ambient environments. After hours, 90% of the initial PCE can still be maintained. The study also demonstrated a large 1.00 cm2 device, PCEwas 2.03%.
The lead-free, air-stable, and mass production processible properties make it a promising selection for photovoltaic materials.
Figure 1. Band structure analysis of each layer in the photovoltaic device using ultraviolet photoelectron spectroscopy: (a) pristine meso-TiO2 and meso Sn:TiO2 electron transporting layers, (b) Ag,Bil, (c) PTAA and Li-TFSI doped PTAA hole transporting layers, and (d) the band diagram of an entire device.
Fig. 2. Photovoltaic performance of devices with meso-TiO2 and meso-metal-doped TiO2 electron transporting layers: (a) PCE distribution of devices with various electron transporting layers. Characterization of electron-only devices with meso-TiO2 and meso-Sn:TiO2 electron transporting layer: (b) J-V curves for the SCLC model fitting, (c) I-V curves of the Ohmic region (1 x V), and (d) J-V2 curves of the Child‘s region (J ∞ V²).
Fig. 3. Performance tracing of unencapsulated Ag, Bil, devices in ambient air:
(a) Voc, (b) Jsc, (c) fill factor, and (d) PCE.
Key word: perovskite solar cells, Ag3BiI6 rudorffite solar cell , Lead-free, Blade coat