On the mechanism of appearance of space-charge-limited current in higher manganese silicide (HMS)--HMS and HMS--M structures

Abstract

Experimental photocurrent-voltage characteristics of higher manganese silicide (HMS)-Si Mn -HMS and HMS-Si Mn -M structures have been analysed. The mechanism is considered of current flow under illumination with hν ≤ E g radiation. In the structures under study, the space-charge-limited-current (SCLC) mode is realized in the temperature interval 77-270 K, and photocurrent-voltage characteristics show regions of linear and quadratic dependence and a region of steep current rise. The high photosensitivity of these structures and the occurrence of SCLC is explained by (i) formation, in the subsurface region of Si diffusion-doped with manganese, of a contact layer of HSM injecting holes into silicon; and (ii) the fact that at low temperature the high-resistance base region of the structures illuminated with intrinsic radiation becomes a low-resistance conducting layer, and a transition layer in which the SCLC mode is realized is formed at the HMS-Si Mn phase boundary.

Influence of structural defects in silicon on formation of photosensitive heterostructures Mn4Si7-Si-Mn4Si7 and Mn4Si7-Si-M

“…If, on cooling, the structure was illuminated with white light, the process was of a different nature, namely: when the temperature of the structure decreased to (170-250) K, the current flow initially decreased by several orders of magnitude relative to the values of current determined at room temperature, after further cooling to 80 K, a sharp increase in the photocurrent values was observed (by 2-3 orders of magnitude higher than the values of the photocurrent taken at room temperature, see Figure 1, curve 4). The photovoltaic-ampere characteristic (PVAC) of the heterostructure had a linear section, a quadratic section and a section of a sharp current increase [7,8]. Such heterostructures were characterized by such photoelectric phenomena as infrared damping, temperature quenching, long-term relaxation of residual conductivity, enhancement of phase transitions, and temperature-electric instabilities [8][9][10].…”

ВЛИЯНИЕ СТРУКТУРНЫХ ДЕФЕКТОВ В КРЕМНИИ НА ФОРМИРОВАНИЕ ФОТОЧУВСТВИТЕЛЬНЫХ ГЕТЕРОСТРУКТУР Mn4Si7−Si<Mn>−Mn4Si7 и Mn4Si7-Si<Mn>−M

“…Фотовольтамперная характеристика (ФВАХ) гетероструктуры имела линейный, квадратичный и участок резкого роста тока [7,8].…”

Photoelectric properties of higher manganese silicide (HMS)-SilangleMnrangle-M structures

“…0268-1242/99/111012+06$30.00 © 1999 IOP Publishing Ltd Photoelectric properties of (HMS)-Si Mn -M structures q q q q q q q q q q q q q q q q q q q 5 10 15 Further, HMS-Si Mn structures were fabricated by the procedure described in detail in [6,7]. This procedure involved removal of subsurface layers no less than 20 µm thick over the whole sample surface, except a single face.…”

“…As already mentioned, HMS is formed in the subsurface region and then an intermediate layer including a polycrystalline layer and a newly formed epitaxial silicon layer with negligible concentration of electrically active impurity atoms of manganese and boron appears at the interface [6,10,11]. And only after this intermediate layer lies the uniformly doped bulk material [6,7,12].…”

“…Recently, photocurrent-voltage characteristics of higher manganese silicide (HMS)-Si Mn -HMS and HMS-Si Mn -M structures have been studied in the fundamental absorption region in a wide temperature range and a conduction mechanism has been proposed [6]. This mechanism takes into account the formation of a higher manganese silicide layer in the subsurface region of silicon during its diffusion doping with Mn [7,8].…”