Simultaneous band gap narrowing and carrier lifetime prolongation of   organic-inorganic trihalide perovskites
  The organic-inorganic hybrid lead trihalide perovskites have been emerging as the most attractive photovoltaic material. As regulated by Shockley-Queisser theory, a formidable materials science challenge for the next level improvement requires further band gap narrowing for broader absorption in solar spectrum, while retaining or even synergistically prolonging the carrier lifetime, a critical factor responsible for attaining the near-band gap photovoltage. Herein, by applying controllable hydrostatic pressure we have achieved unprecedented simultaneous enhancement in both band gap narrowing and carrier lifetime prolongation (up to 70~100% increase) under mild pressures at ~0.3 GPa. The pressure-induced modulation on pure hybrid perovskites without introducing any adverse chemical or thermal effect clearly demonstrates the importance of band edges on the photon-electron interaction and maps a pioneering route towards a further boost in their photovoltaic performance. 
Lingping Kong, Gang Liu, Jue Gong, Qingyang Hu, Richard D. Schaller,   Przemyslaw Dera, Dongzhou Zhang, Zhenxian Liu, Wenge ...
cond-mat.mtrl-sci physics.optics