Topic: Organic-inorganic Lead Halide Perovskite: Photovoltaics and Beyond

Speaker: Prof. Nam-Gyu Park
　　　　School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 440-746, Korea

Abstract:

Since the first report on solid-state perovskite solar cell with power conversion efficiency (PCE) of 9.7% in 2012 reported by Park et al, perovskite solar cell related publications increase exponentially. As a result, more than 8,000 peer-reviewed research papers were published since 2012. Technologically, PCE was improved in a very short period and reached over 22%, indicating that perovskite solar cell is disruptive technology in photovoltaics. Although high PCE is demonstrated, current-voltage hysteresis and stability are critical issues to be solved. In this talk, history and progress in SKKU will be presented. In order to solve issues, methodologies to eliminate hysteresis and/or improve stability will be discussed based on bulk, interfacial and interstitial nano-engineering. We developed a universal method to eliminate the hysteresis, where a severe hysteresis observed usually in normal structure with TiO₂ electron transporting layer was completely removed by interstitial doping to MAPbI₃, FAPbI₃ and mixed cation-anion perovskites. Interfacial nano-engineering is also one of effective methods to improve stability and reduce hysteresis. Surface passivation and low-dimensional interlayer led to significant increase in stability along with substantial reduction in hysteresis. Recent development of low-dose X-ray imaging system employing MAPbI3 will be presented. Finally research direction toward Shockley-Queisser limit is proposed.