Steady-state and time-resolved photoluminescence in microcrystalline silicon

Abstract

A systematic investigation has been made on steady-state and time-resolved photoluminescence (PL) in microcrystalline silicon (μc-Si) at liquid-helium temperature. The steady-state PL spectra on various grain sizes and volume fractions are examined. It is found that the low-energy emission (∼0.76 eV) arises only from the amorphous phase and not from the crystalline phase and the grain boundary regions. The results indicate that the origin of the luminescence is considered to be due to defects created in the amorphous phase resulting from the microcrystallinity which increase with the grain size and/or the volume fraction. It has been shown from the analysis of the time-resolved PL measurement that the recombination transition of carriers of the low- and the high- (∼1.24 eV) energy emissions can be interpreted by a new model.

Photoluminescence in microcrystalline silicon films grown from argon diluted silane

“…Bhat et al [1] suggested that the low-energy PL band is due to the defect-related radiative recombination. Komuro et al [2] suggested that the low-energy PL band is due to the defects created in the amorphous phase. Carius et al [3] and Kalkan et al [4] also proposed that the low-energy PL in lc-Si:H arises from a superposition of different contributions from the defect-related recombination in the crystalline phase.…”

Laser applications in thin-film photovoltaics

“…Furthermore, the high nonradiative recombination rates often require measurements to be performed at cryogenic temperatures. In spite of it all, various photoluminescence studies have contributed to unveil the nature of radiative recombinations in TF PV materials [75][76][77][78].…”

“…Depending on the TF technology, the photoluminescence decays in a ps to ns time scale [75,79,80]. These short decay times are typically resolved with a mode-locked laser and provide some insight into carrier dynamics.…”

“…LIPEE was further developed to study the radial distribution of crystallites in parallel-plate discharges and the influence of the reactor temperature on the formation of silicon crystallites in Ar-SiH 4 discharges. It has been demonstrated that lower reactor temperatures [67,75,79,80] Photothermal deflection spectroscopy Laser beam deflections Sub-bandgap absorption, [81][82][83] defect densities…”

Band-tail photoluminescence in nanocrystalline Si

“…[1][2][3][4][5][6] Blueshift and bandwidth widening of this PL has been found to generally occur with growth conditions favoring higher disorder and smaller grain size. Previous work on c-Si:H and nc-Si:H has shown a dominant PL peak located within 0.8-1.0 eV and with a full width at half maximum ͑FWHM͒ of 0.10-0.15 eV.…”