Optical absorption and photoluminescence (PL) spectra of the layered perovskite semiconductor (C8H17NH3)(2)PbI4 were measured under hydrostatic pressure to 25 GPa in order to investigate the effect of pressure-induced perturbations on the electronic structure and the excitonic states of the two-dimensional sublattice of corner-sharing [PbI6](4-) octahedra. The predominant PL band, which originates from a free exciton state, shirts to lower energies sublinearly with pressure, and then disappears abruptly above P-C congruent to 12 GPa. The exciton absorption hand also disappears at P-C, and a broad absorption tail appears at a higher energy above P-C. It is found that the pressure dependence of the band gap energy above P-C is significantly different from that of the exciton band energy below P-C, indicating that the electronic band structure of the two-dimensional sublattice changes at P-C. A large hysteresis on the recovery of the exciton band was observed upon decreasing pressure.
|Number of pages||6|
|Journal||physica status solidi (b) – basic solid state physics|
|Publication status||Published - Jan 2001|
|Event||9th International Conference on High Pressure Semiconductor Physics (HPSP9) - SAPPORO, Japan|
Duration: 24 Sep 2000 → 28 Sep 2000