The organic-inorganic hybrid lead trihalide perovskites have been emerging as the most attractive photovoltaic materials. As regulated by Shockley-Queisser theory, a formidable materials science challenge for improvement to the next level 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% to ∼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 toward a further increase in their photovoltaic performance. . The remarkable photovoltaic performance is attributed to its strong and broad (up to ∼800 nm) light absorption (10), as well as the long diffusion lengths facilitated by its extraordinarily long carrier lifetimes (∼100 ns in thin film) despite its modest mobility (11,12,15,16). To further approach the Shockley-Queisser limit (17, 18), it is highly desirable to tune the crystal structure of perovskite in the way that can synergistically narrow down the band gap for broader solar spectrum absorption (10) and prolong carrier lifetime for greater photovoltage (7,11,12,15,16). However, compositional modification suffers from challenges, such as the largely shortened carrier lifetime (∼50 ps), and thus considerable loss of photovoltage upon the replacement of Pb by Sn (5, 19), or the largely widened band gap, and thus low photocurrent when I is substituted with Br or Cl (16). It also has been demonstrated that using formamidinium (FA) cations instead of MA cations in organic-inorganic perovskite materials narrows down the band gap; however, a shorter carrier lifetime is generated inevitably (20). In fact, to date, there is no reported method for simultaneously achieving band-gap narrowing and carrier-lifetime prolongation for MAPbI 3 .Nonetheless, the chance is to rescrutinize the band structure of MAPbI 3 . The relatively long carrier lifetimes of 10 2 to ∼10 3 ns observed in MAPbI 3 single crystals originate from their unique defect physics (21). First-principles calculations demonstrated that the readily formed point defects such as interstitial MA ions and/or Pb vacancies create shallow states with trap energy less than 0.05 eV below the conduction band minimum (CBM), or above the valence band maximum (VBM), rather than detrimental deep traps at the middle of the forbidden zone, which typically lead to nonradiative recombination (21). The uneven distribution of the trap states has been identified further by in-depth electronic characterization of MAPbI 3 perovskite single crystals, concluding that the traps are close to the conduction an...