Zr‐Doped Indium Oxide (IZRO) Transparent Electrodes for Perovskite‐Based Tandem Solar Cells
byErkan Aydin, Michele De Bastiani, Xinbo Yang, Muhammad Sajjad, Faisal Aljamaan, Yury Smirnov, Mohamed Nejib Hedhili, Wenzhu Liu, Thomas G Allen, Lujia Xu, Emmanuel Van Kerschaver, Monica Morales-Masis, Udo Schwingenschlögl, Stefaan De Wolf
Aydin, E., De Bastiani, M., Yang, X., Sajjad, M., Aljamaan, F., Smirnov, Y., Hedhili, M. N., Liu, W., Allen, T. G., Xu, L., Kerschaver, E. V., Morales‐Masis, M., Schwingenschlögl, U., De Wolf, S., Zr‐Doped Indium Oxide (IZRO) Transparent Electrodes for Perovskite‐Based Tandem Solar Cells. Advanced Functional Materials 2019, 1901741.
This study unveils the potential of the Zr‐doped indium oxide (IZRO) transparent electrodes for perovskite-based tandem solar cells due to its very high electron mobility (up to ≈77 cm2 V−1 s−1), highly infrared transparency and very low sheet resistance (≈18 Ω ohm/sq)
Parasitic absorption in transparent electrodes is one of the main roadblocks to enabling power conversion efficiencies (PCEs) for perovskite‐based tandem solar cells beyond 30%. To reduce such losses and maximize light coupling, the broadband transparency of such electrodes should be improved, especially at the front of the device. Here, the excellent properties of Zr‐doped indium oxide (IZRO) transparent electrodes for such applications, with improved near‐infrared (NIR) response, compared to conventional tin‐doped indium oxide (ITO) electrodes, are shown. Optimized IZRO films feature a very high electron mobility (up to ≈77 cm2 V−1 s−1), enabling highly infrared transparent films with a very low sheet resistance (≈18 Ω □−1 for annealed 100 nm films). For devices, this translates in a parasitic absorption of only ≈5% for IZRO within the solar spectrum (250–2500 nm range), to be compared with ≈10% for commercial ITO. Fundamentally, it is found that the high conductivity of annealed IZRO films is directly linked to promoted crystallinity of the indium oxide (In2O3) films due to Zr‐doping. Overall, on a four‐terminal perovskite/silicon tandem device level, an absolute 3.5 mA cm−2 short‐circuit current improvement in silicon bottom cells is obtained by replacing commercial ITO electrodes with IZRO, resulting in improving the PCE from 23.3% to 26.2%.
high mobilityimproved near-infrared responseindium zirconium oxideperovskite tandem solar cellstrqnsparent electrodes