  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.
