Photovoltaic & Optoelectronic Device Group: publications

A piperidinium salt stabilizes efficient metal-halide perovskite solar cells.

Science (New York, N.Y.) Nature Research 369:6499 (2020) 96-102

Authors:

Yen-Hung Lin, Nobuya Sakai, Peimei Da, Jiaying Wu, Harry C Sansom, Alexandra J Ramadan, Suhas Mahesh, Junliang Liu, Robert DJ Oliver, Jongchul Lim, Lee Aspitarte, Kshama Sharma, Pk Madhu, Anna B Morales-Vilches, Pabitra K Nayak, Sai Bai, Feng Gao, Chris RM Grovenor, Michael B Johnston, John G Labram, James R Durrant, James M Ball, Bernard Wenger, Bernd Stannowski, Henry J Snaith

Abstract:

Longevity has been a long-standing concern for hybrid perovskite photovoltaics. We demonstrate high-resilience positive-intrinsic-negative perovskite solar cells by incorporating a piperidinium-based ionic compound into the formamidinium-cesium lead-trihalide perovskite absorber. With the bandgap tuned to be well suited for perovskite-on-silicon tandem cells, this piperidinium additive enhances the open-circuit voltage and cell efficiency. This additive also retards compositional segregation into impurity phases and pinhole formation in the perovskite absorber layer during aggressive aging. Under full-spectrum simulated sunlight in ambient atmosphere, our unencapsulated and encapsulated cells retain 80 and 95% of their peak and post-burn-in efficiencies for 1010 and 1200 hours at 60° and 85°C, respectively. Our analysis reveals detailed degradation routes that contribute to the failure of aged cells.

Direct Silicon Heterostructures With Methylammonium Lead Iodide Perovskite for Photovoltaic Applications

IEEE Journal of Photovoltaics Institute of Electrical and Electronics Engineers (IEEE) 10:4 (2020) 945-951

Authors:

Silvia Mariotti, Mohammed Al Turkestani, Oliver S Hutter, Georgios Papageorgiou, Jonathan D Major, Jack Swallow, Pabitra K Nayak, Henry J Snaith, Vinod R Dhanak, Ken Durose

High‐Throughput Characterization of Perovskite Solar Cells for Rapid Combinatorial Screening

Solar RRL Wiley 4:7 (2020)

Authors:

Maciej Adam Surmiak, Tian Zhang, Jianfeng Lu, Kevin James Rietwyk, Sonia Ruiz Raga, David Patrick McMeekin, Udo Bach

Light intensity modulated photoluminescence for rapid series resistance mapping of perovskite solar cells

Nano Energy Elsevier 73 (2020) 104755

Authors:

Kevin J Rietwyk, Boer Tan, Adam Surmiak, Jianfeng Lu, David P McMeekin, Sonia R Raga, Noel Duffy, Udo Bach

Revealing factors influencing the operational stability of perovskite light-emitting diodes

ACS Nano American Chemical Society 14:7 (2020) 8855-8865

Authors:

Jonathan H Warby, Bernard Wenger, Alexandra J Ramadan, Robert Oliver, Harry Sansom, Ashley Marshall, Henry Snaith

Abstract:

Light-emitting diodes (LEDs) made from metal halide perovskites have demonstrated external electroluminescent quantum efficiencies (EQEEL) in excess of 20%. However, their poor operational stability, resulting in lifetimes of only tens to hundreds of hours, needs to be dramatically improved prior to commercial use. There is little consensus in the community upon which factors limit the stability of these devices. Here, we investigate the role played by ammonium cations on the operational stability. We vary the amount of phenylethylammonium bromide, a widely used alkylammonium salt, that we add to a precursor solution of CsPbBr3 and track changes in stability and EQEEL. We find that while phenylethylammonium bromide is beneficial in achieving high efficiency, it is highly detrimental to operational stability. We investigate material properties and electronic characteristics before and after degradation and find that both a reduction in the radiative efficiency of the emitter and significant changes in current–voltage characteristics explain the orders of magnitude drop in the EQEEL, which we attribute to increased ionic mobility. Our results suggest that engineering new contacts and further investigation into materials with lower ionic mobility should yield much improved stability of perovskite LEDs.

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