Deposition reactors for solar grade silicon: A comparative thermal analysis of a Siemens reactor and a fluidized bed reactor

Abstract

Polysilicon production costs contribute approximately to 25-33% of the overall cost of the solar panels and a similar fraction of the total energy invested in their fabrication. Understanding the energy losses and the behaviour of process temperature is an essential requirement as one moves forward to design and build large scale polysilicon manufacturing plants. In this paper we present thermal models for two processes for poly production, viz., the Siemens process using trichlorosilane (TCS) as precursor and the fluid bed process using silane (monosilane, MS). We validate the models with some experimental measurements on prototype laboratory reactors relating the temperature profiles to product quality. A model sensitivity analysis is also performed, and the effects of some key parameters such as reactor wall emissivity, gas distributor temperature, etc., on temperature distribution and product quality are examined. The information presented in this paper is useful for further understanding of the strengths and weaknesses of both deposition technologies, and will help in optimal temperature profiling of these systems aiming at lowering production costs without compromising the solar cell quality.

Identification of higher order silanes during monosilane pyrolysis using gas chromatography-mass spectrometry

“…Despite their proven capability of producing polysilicon with significantly lower energy demand than the Siemens reactor [3,6,7], these monosilane based reactor technologies encounter limitations related to dust formation during the monosilane pyrolysis process [6][7][8]. Dust (fines) is formed when reactant gas molecules decompose homogeneously (in the gas phase), rather than heterogeneously (on a surface) [9,10].…”

The effect of nanoparticle morphology in the filtration efficiency and saturation of a silicon beads fluidized bed

“…The unit operation has traditionally relied on the Siemens process, 2 which is effective in achieving the required Si purity but requires a considerable energy consumption, causing polysilicon so produced to be costly. 3 An alternative to the Siemens process for synthesis of polysilicon (poly Si) is the fluidized bed reactor (FBR). FBR technology can be used to produce poly Si at lower cost and using less energy than the Siemens reactor.…”

“…FBR technology can be used to produce poly Si at lower cost and using less energy than the Siemens reactor. 3 This is a consequence of the FBR´s intrinsically higher thermal efficiency, lower temperature gradients, the higher throughput per volume of reactor and the fact that FBR is a continuous process whereas Siemens is a batch process. Also FBRs can be optimized to achieve high efficiency of heat and mass transfer between solid particles and the gas.…”

Spectroscopic and Computational Analyses of Liquid–Liquid Interfacial Reaction Mechanism of Boric Acid Esterification with 2,2,4-Trimethyl-1,3-pentanediol in Boron Extraction Processes

“…Furthermore, white silica ore, which is currently the Si source for the process, has limited availability compared with the recent high demands for SOG-Si. This has led to the necessary development of the alternative processes optimal for SOG-Si, the possibility of which has been discussed in past studies. − …”