Screen‐print selective diffusions for high‐efficiency industrial silicon solar cells

Abstract

Screen‐print diffusion pastes present an industrially applicable alternative to conventional techniques of dopant deposition. Several commercially available screen‐print dopant pastes are assessed for their suitability in forming heavy selective diffusions for use under metal contacts in silicon solar cells. Pastes are assessed in terms of their ease of application, their ability to form heavy diffusions with low sheet resistances, and their ability to maintain high post‐diffusion wafer lifetimes. Potential for the use of dopant pastes in high‐efficiency solar cell devices is investigated using photoconductance (PC) measurements and photoluminescence (PL) images. It is found that under certain conditions, screen‐print dopant pastes, particularly phosphorus paste, have potential to form effective selective diffusions without significantly compromising performance in high‐efficiency solar cells. Copyright © 2007 John Wiley & Sons, Ltd.

Gettering in multicrystalline silicon wafers with screen‐printed emitters

“…The screen-printing parameters for uniform single-sided emitters were optimised in our previous work [5]. The diffusion process was carried out in the same quartz tube furnace at a temperature of about 820 8C with constant gas flow and time [9,10]. Later, the phosphorus silicate glass (PSG) formed as a byproduct of the diffusion process was removed along with the residues (if there were any) by a dip in diluted hydrofluoric acid (HF).…”

Silicon ink selective emitter process: Optimization of selectively diffused regions for short wavelength response

“…A number of different approaches have been proposed to realize selective emitter structures, such as buried contact cell process, diffusion-barrier approaches, screen-printed doped paste, emitter etch-back approach and laser doping (see e.g. [1][2][3]). …”

Effects of the flow rate of O2 annealing ambient on structural and electrical properties of n+ emitter junctions formed using screen‐printed phosphorus diffusion process

“…Among them, screen printing process has been received a lot of attentions due to its simplicity and rapidness for forming high quality n+ emitter region without the edge isolation process. Furthermore, it offers the facilitation to form selective heavily doped regions without the additional process for diffusion mask openings using laser processing or photolithography before diffusion process . Such a feature enables the screen printing process to be a valuable technique for the realization of selective emitter solar cells with low module production costs.…”