Prof. Nazeeruddin - New Horizons for Photovoltaics: Perovskite Solar Cells

Perovskite solar cells have created enormous excitement among the photovoltaic community after the seminal work of Miyasaka and co-workers¹ and followed by solid-state perovskite solar cells.^2-3 Several groups have demonstrated that the Methylammonium lead triiodide perovskite (CH₃NH₃PbI₃) have remarkable properties such as panchromatic absorption with large molar extinction coefficient, long carrier diffusion length with low non-radiative recombination rates, and an electron and hole transporter in both mesoscopic networks and planar heterojunctions. The band gap of the CH₃NH₃PbI₃ perovskite absorber layer can be tuned by using various cations and anions, and deposited using a broad range of techniques. There are several perovskite solar cell device architectures, but the highest reported efficiency over 20% is based on n-i-p structure, where the perovskite is an intrinsic semiconductor, TiO₂ as an electron acceptor (n-type layer), and polytertiary aryl amine polymer (PTAA) or 2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenylamine)-9,9’-spirobifluorene as hole transporter (p-type layer) yielding power conversion efficiency of 20%.⁴ Nevertheless, these HTM’s are relatively expensive and limits the long-term stability of the perovskite solar cell device under light and heat soaking conditions. Therefore several groups have developed novel hole transporting materials based on molecularly engineered organic,^5-6 and inorganic,⁷ which yields comparable power conversion efficiency of state-of-the-art HTM’s under AM 1.5 conditions.

Learn more about Prof. Nazeeruddin's work