Amorphous silicon

About: Amorphous silicon is a research topic. Over the lifetime, 26777 publications have been published within this topic receiving 423234 citations.

Calculated temperature distribution during laser annealing in silicon and cadmium telluride

Abstract: By solving the time-dependent heat flow equation, the temperature reached by silicon and cadmium telluride surface layers under high power density ruby laser pulsed illumination, is calculated. The results are presented in directly useful figures allowing the determination of the surface temperature, its evolution towards the bulk as a function of time... In particular, it should be noticed that for a 25 ns half-power width, pulses of 0.8J/cm2 are sufficient to melt the top of an amorphous silicon layer, this value becomes noticeably lower for cadmium telluride.

Optical and transport studies on thin microcrystalline silicon films prepared by very high frequency glow discharge for solar cell applications

Abstract: The initial growth stage of phosphorus doped microcrystalline silicon films prepared by plasma enhanced chemical vapor deposition with different plasma excitation frequencies in the range 13.56–116 MHz was studied by Raman and infrared spectroscopy, optical transmission and reflection, and conductivity measurements. The sensitivity of Raman spectroscopy and optical reflection on Si crystallites in the initial growth regime is compared and optical reflection at 4.5 eV is proposed as an easy and reliable tool for this investigation. While the crystallite formation on amorphous silicon substrates at 13.56 MHz is delayed in comparison with glass, SiO2 and chromium substrates, nucleation of the crystalline phase on amorphous silicon is found to be greatly enhanced at higher plasma excitation frequencies. On the other hand, for deposition on glass, SiO2, and chromium at frequencies equal to or higher than 70 MHz, increased porosity is found in the initial growth region. The results are interpreted within a mode...

Amorphous silicon thin-film transistors on steel foil substrates

Abstract: We report the successful fabrication of high-quality a-Si:H thin-film transistors (TFTs) on stainless steel foil substrates. TFTs with an inverted-staggered structure were grown on 200-/spl mu/m thick stainless steel foil. These TFTs show typical ON/OFF current ratios of 10/sup 7/, OFF currents on the order of 10/sup -12/ A, good linear and saturation current behavior, subthreshold slopes of 0.5 V/decade, and linear channel mobilities of 0.5 cm/sup 2//V. In addition, we have demonstrated that these TFTs are capable of withstanding significant mechanical shocks, as well as macroscopic deformation of the substrate, while remaining functional. This work demonstrates that transistor circuits can be made on a flexible, nonbreakable substrate. Such circuits would be highly useful in reflective or emissive displays, and in other applications that require rugged macroelectronic circuits.

UV-nano-imprint lithography technique for the replication of back reflectors for n-i-p thin film silicon solar cells

Abstract: Texturing of interfaces in thin film silicon solar cells is essential to enhance the produced photocurrent and thus the efficiencies.AUVnano-imprint-lithography (UV-NIL) replication processwas developed to prepare substrates with textures that are suitable for the growth of n-i-p thin film silicon solar cells. Morphological and optical analyses were performed to assess the quality of the replicas. A comparison of single junction amorphous solar cells on the original structures and on their replicas on glass revealed good light trapping and excellent electrical properties on the replicated structures. A tandem amorphous silicon/amorphous silicon (a-Si/a-Si) cell deposited on a replica on plastic exhibits a stabilized efficiency of 8.1% and a high yield of 90% of good cells in laboratory conditions. It demonstrates the possibility to obtain appropriate structure on low cost plastic substrate. Copyright © 2010 John Wiley & Sons, Ltd.