Time-resolved photoluminescence of red mercuric iodide

Abstract

Discrimination of local radiative and nonradiative recombination processes in an InGaN/GaN single-quantum-well structure by a time-resolved multimode scanning near-field optical microscopy Time-resolved photoluminescence ͑TRPL͒ spectrum of red mercuric iodide single crystal for two kinds of different grown methods was measured and compared at low temperatures. The different spectral structures were found for the different grown crystals. At the band-gap region two kinds of photoluminescence were similar. Sharp near band-gap luminescence due to the radiative annihilation of free and bound excitons was observed at 530 nm and a luminescent tail band that originated from the nonradiative annihilation of bound excitons appeared at 540 nm for two crystals. The 560 nm band was observed for the sublimation crystals and a broad luminescent band appeared at 630 nm for the acetone solution crystals, respectively. The TRPL experiment of the near band-gap lines revealed that luminescence comprised a fast and a slow decay component and showed several relaxation processes in free and bound exciton annihilation. The temporal behavior of the tail band revealed the same regularity for two kinds of crystals. The behavior was described with the rate equations and was obviously different from the band-gap luminescence. The 560 nm band had much slower decay than near band-gap decay. At the 630 nm band PL intensity was expressed as I(t) ϭt Ϫn(r) . The experiment of the red band showed clearly that the luminescence was ascribed to the radiative recombination of donor-acceptor pairs.

Anomalous kinetics of attractiveA+B→0reactions

“…In reality in which oppositely charged particles recombinate into inert particles such as electron-hole recombinations in photoluminescence [15] and particleantiparticle reactions in the early universe [1], the local attractive interaction between opposite species should be much more important than the global uniform biases. In this paper, we investigate the kinetics of A + B → 0 reaction with the attractive interaction between opposite species in one dimension, which may model composite systems of oppositely charged particles much more effectively than the model with the global and uniform drift.…”

Growth of mercuric iodide crystals

“…In order to look for a cheaper fabrication process, we used the solvent evaporation technique, which was already used for crystals growth [1,15].…”

“…Many studies on high band gap semiconductor were published in the last decades, mainly for applications in X-and gamma-ray detectors [1][2][3][4][5]. The desired properties of the material are a high band gap (that leads to a low background current) and a high atomic number (that leads to high stopping power, and thus detection efficiency).…”

Iodeto de mercúrio (HgI2) para aplicações em detectores de radiação.

“…O material utilizado é um semicondutor que já vem sendo aplicado como cristal (tipo bulk) em detectores de tais radiações, mas utilizando-se de métodos de deposição tais como evaporação térmica, physical vapor transport(PVT), physical vapor deposition (PVD) e evaporação de solvente [4][5][6][7][8][9][10][11][12]. O número de estudo de filmes finos para aplicações em detectores vem crescendo nas últimas décadas por conta da microeletrônica.…”