Deep center EL2 and anti-Stokes luminescence in semi-insulating GaAs

Abstract

We have observed efficient photoluminescence upconversion in semi-insulating GaAs. This upconversion is apparently associated with a two-step excitation of the deep level EL2 as indicated by the excitation spectrum. Assessment of these results along with results in the literature suggests that this center is due to an arsenic antisite defect. Line shape analysis indicates that clustering of acceptors occurs near the site of the defect. These results provide insight into the agents responsible for the semi-insulating property of undoped GaAs.

Photon energy up-conversion in colloidal TiO2 nanorods

“…Such UC effects have been reported in bulk semiconductors [3,4], heterostructures [5][6][7][8][9][10][11], and selfassembled quantum dots [12,13]. For UC in bulk semiconductors and heterostructures, the proposed mechanism involves either two-step photoexcitation process [7][8][9]11] or Auger recombination that ionizes carriers to the higher bandgap region where they undergo radiative recombination [5,6,10].…”

Photoluminescence of Anatase and Rutile TiO2 Particles

“…Such UC effects have been reported in bulk semiconductors, 29,30 heterostructures, [31][32][33][34][35][36][37] and self-assembled quantum dots. 38,39 For UC in bulk semiconductors and heterostructures, the proposed mechanism involves either a two-step photoexitation process [33][34][35]37 or an Auger recombination that ionizes carriers to the higher band gap region where they undergo radiative recombination.…”

Studies of Grown-In Defects Versus Growth Parameters in III-V Compound Semiconductors.

“…From the experimental evidence, it can be ++ shown that EL2a trap is due to antisite defect, AsGa + , formed during the S! post-grown cooling [ 94,99], as will be discussed further in next section.…”