Properties of Strong Luminescence at 0.93 eV in Solar Grade Silicon

Abstract

We report on 0.93 eV luminescence observed in multicrystalline silicon. The spectral line is close to the well known D3 one, but its properties are different. The new feature shows a remarkable intensity at room temperature, exceeding the intensity of the band to band radiative transition. Moreover, it appears as a single line in the entire temperature range 10-300K, in contrast to the D3, which is usually accompanied by D4. Cathodoluminescence (CL) and electron beam induced current (EBIC) micrographs revealed that the centers causing 0.93 eV emission are irregularly distributed along certain grain boundaries. Electron backscattering diffraction examination showed that the 0.93 eV luminescence appears at grain boundaries characterized by a lattice rotation around a <344> axis. The EBIC contrast at those irregularities indicates strong total recombination. Based on an analysis of the temperature dependence of the CL intensity and the EBIC contrast we obtained an activation energy of about 120 meV.

1320 nm Light Source From Deuterium Treated Silicon

“…Nevertheless, the identification of the origin of the band at 1320 nm is not straightforward. It is located around D3 dislocation luminescence line of Si but D3 was identified as the phonon replica of D4 line thus appearing together at low temperature [4]. Actually, we have shown that this band can be de-convoluted to 1306 nm (0.949 eV) and 1391 nm (0.891 eV) peaks with a band distance of 58 meV corresponding to transverse optical TO-phonon energy as shown at the insert of Fig.…”

“…light emission source finds its origin at dislocations generated on the Si wafer [4], [5]. Devices fabricated from this type of source reveals rather broad bands having a number of emission peaks between 800-1800 nm [5], [6].…”

“…Due to its indirect bandgap nature, light emission from Si in NIR can usually be observed at low temperature, but without application possibility. The intensity of the source is relatively faint or not measurable at 300 K. One type of light emission source finds its origin at dislocations generated on the Si wafer [4], [5]. Devices fabricated from this type of source reveals rather broad bands having a number of emission peaks between 800-1800 nm [5], [6].…”