Microsecond Carrier Lifetimes, Controlled p-Doping, and Enhanced Air Stability in Low-Bandgap Metal Halide Perovskites

[Image: see text] Mixed lead–tin halide perovskites have sufficiently low bandgaps (∼1.2 eV) to be promising absorbers for perovskite–perovskite tandem solar cells. Previous reports on lead–tin perovskites have typically shown poor optoelectronic properties compared to neat lead counterparts: short...

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Detalles Bibliográficos
Autores principales: Bowman, Alan R., Klug, Matthew T., Doherty, Tiarnan A. S., Farrar, Michael D., Senanayak, Satyaprasad P., Wenger, Bernard, Divitini, Giorgio, Booker, Edward P., Andaji-Garmaroudi, Zahra, Macpherson, Stuart, Ruggeri, Edoardo, Sirringhaus, Henning, Snaith, Henry J., Stranks, Samuel D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2019
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748266/
https://www.ncbi.nlm.nih.gov/pubmed/31544151
http://dx.doi.org/10.1021/acsenergylett.9b01446
Descripción
Sumario:[Image: see text] Mixed lead–tin halide perovskites have sufficiently low bandgaps (∼1.2 eV) to be promising absorbers for perovskite–perovskite tandem solar cells. Previous reports on lead–tin perovskites have typically shown poor optoelectronic properties compared to neat lead counterparts: short photoluminescence lifetimes (<100 ns) and low photoluminescence quantum efficiencies (<1%). Here, we obtain films with carrier lifetimes exceeding 1 μs and, through addition of small quantities of zinc iodide to the precursor solutions, photoluminescence quantum efficiencies under solar illumination intensities of 2.5%. The zinc additives also substantially enhance the film stability in air, and we use cross-sectional chemical mapping to show that this enhanced stability is because of a reduction in tin-rich clusters. By fabricating field-effect transistors, we observe that the introduction of zinc results in controlled p-doping. Finally, we show that zinc additives also enhance power conversion efficiencies and the stability of solar cells. Our results demonstrate substantially improved low-bandgap perovskites for solar cells and versatile electronic applications.