Improvgement of Voc for μc-Si: H/poly-Si p—n junction solar cells

In situdoping of silicon deposited by LPCVD: pressure influence on dopant incorporation mechanisms

“…Consequently, the limiting stage of the process of polysilicon film growth is the surface reaction, and a decrease of the silane concentration near the surface, due to a high flow rate, will not decrease R: this is the case when the silane pressure is low, as observed in figure 2. Suppose now that deposition proceeds through the mechanism of equation (2) and that silylene contributes most to the silicon growth [9]: silylene is known to decompose very rapidly on a surface whose temperature is raised to 550 • C. Therefore the growth is limited by the gas mass transfer. Thus, as a high flow rate leads to a weak concentration of silylene near the surface of the substrates, R should be reduced; this is true in the range of high pressure (figure 2) and therefore confirms then the presence of SiH 2 under these growth conditions.…”

“…Thin polysilicon films have found several applications as gates or electrodes in VLSI since the beginning of the 1970s and in the last few years as the active layer of MOSFETs dedicated to active matrix displays [1]. More recently, a lot of studies concerning its photovoltaic properties have started, making it a potential substitute for amorphous hydrogenated silicon [2,3].…”

Influence of the Doping Gas on the Axial Uniformity of the Growth Rate and the Electrical Properties of LPCVD In-Situ Doped Polysilicon Layers

“…More recently, its interest increased in the studies concerning solar cells because of its potentially better electrical properties than amorphous silicon which is metastable [2,3]. However, having a weaker absorption, it is necessary either to deposit thicker layers of polysilicon, thus to increase the growth rate, or to deposit it on a very large area.…”

From amorphous to microcrystalline silicon: Moving from one to the other by halogenated silicon plasma chemistry

“…Those studies led, about ten years later, to µc-Si/a-Si:H p-n junction solar cells with improved properties [11,12]. In 1994, the preparation of a fully microcrystalline (µc-Si:H) silicon pi-n single-junction solar cell with new striking advantages compared to amorphous silicon (a-Si:H) was achieved [13].The main reason driving the transition from a-Si to µc-Si:H was the fact that the latter showed no light induced degradation unlike a-Si:H. Because of the favorable combination of the improved photostability, higher carrier mobility and lower optical absorption, µc-Si films are being used not only for solar cells but also as carrier injection layers in thin film transistors.…”