Charge-carrier dynamics in hybrid metal halide perovskites (Conference Presentation)
Proceedings of SPIE--the International Society for Optical Engineering SPIE, the international society for optics and photonics (2016) 99230d-99230d-1
Photon recycling in Lead-Iodide Perovskite solar cells (Conference Presentation)
Proceedings of SPIE--the International Society for Optical Engineering SPIE, the international society for optics and photonics (2016) 99370i-99370i-1
Investigating the role of 4-tert butylpyridine in perovskite solar cells
Advanced Energy Materials Wiley 7:1 (2016) 1601079
Abstract:
The majority of hole鈥恡ransporting layers used in n鈥恑鈥恜 perovskite solar cells contain 4鈥恡ert butylpyridine (tBP). High power鈥恈onversion efficiencies and, in particular, good steady鈥恠tate performance appears to be contingent on the inclusion of this additive. On the quest to improve the steady state efficiencies of the carbon nanotube鈥恇ased hole鈥恡ransporter system, this study has found that the presence of tBP results in an extraordinary improvement in the performance of these devices. By deconstructing a prototypical device and investigating the effect of tBP on each individual layer, the results of this study indicate that this performance enhancement must be due to a direct chemical interaction between tBP and the perovskite material. This study proposes that tBP serves to p鈥恉ope the perovskite layer and investigates this theory with poling and work function measurements.Research update: Strategies for improving the stability of perovskite solar cells
APL Materials AIP Publishing 4:9 (2016) 091503
Abstract:
The power-conversion efficiency of perovskite solar cells has soared up to 22.1% earlier this year. Within merely five years, the perovskite solar cell can now compete on efficiency with inorganic thin-film technologies, making it the most promising of the new, emerging photovoltaic solar cell technologies. The next grand challenge is now the aspect of stability. The hydrophilicity and volatility of the organic methylammonium makes the work-horse material methylammonium lead iodide vulnerable to degradation through humidity and heat. Additionally, ultraviolet radiation and oxygen constitute stressors which can deteriorate the device performance. There are two fundamental strategies to increasing the device stability: developing protective layers around the vulnerable perovskite absorber and developing a more resilient perovskite absorber. The most important reports in literature are summarized and analyzed here, letting us conclude that any long-term stability, on par with that of inorganic thin-film technologies, is only possible with a more resilient perovskite incorporated in a highly protective device design.Perovskite-perovskite tandem photovoltaics with optimized bandgaps
(2016)