Absorption spectra of Se and HgI2 chains in channels of AlPO4-5 single crystal

Abstract

The absorption spectra are reported for isolated Se and HgI2 semiconductor chains accommodated in AlPO4-5 (AFI) channels of diameter 7.3 Å. The lowest electronic excitation states of the isolated chains are shifted to higher energy from the band edge transitions of their bulk crystals. The blue shifts are qualitatively explained by the quantum confinement effects of carriers in a one-dimensional wire. The experimental result of the Se/AFI is in good agreement with the theoretical expectation based on the effective-mass-approximation. The result of the HgI2/AFI, however, does not agree with the calculation. The different behaviors of the Se/AFI and the HgI2/AFI are expected to result from their different electronic structures.