Direct write contacts for solar cells

1979

Thb report war p n~m d as M account of work sponoorcd by thc United States Government. Neither the United States nor the Uruted States Department of Enetgy, nor any of their employees, nor any of their contractors, subcontractors, or their employees. makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus. product or process disclosed, or represents that its use would not infringe privately owned rights nR1. No. 86/ORO No. SF

A comparison of the loss mechanisms in screen-printed solar cells relative to buried contact cells and cells with photolithography-defined contacts is presented in this paper. Model calculations show that emitter recombination accounts for about 0.5% absolute efficiency loss in conventional screen-printed cells with low-sheet-resistance emitters. Ohmic contact to highsheet-resistance emitters by screen-printing has been investigated to regain this efficiency loss.

Progress in Photovoltaics Research and Applications, 1999

Consolidated tables showing an extensive listing of the highest independently con-®rmed eciencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since January 1999 are brie¯y described.

2002

Direct writing of solar cell components is an attractive processing approach. We have fabricated a 6.8% Si solar cell using silver ink based electrodes. Ohmic contact through the antireflection (AR) coating was obtained with pure Ag electrodes at 850 0 C. We also report on highly conductive silver metallizations and initial results on direct-write TCO demonstrating a 100micron spatial resolution produced by inkjet printing.

Progress in Photovoltaics Research and Applications, 1998

2008 33rd IEEE Photovolatic Specialists Conference, 2008

Using direct-write approaches in photovoltaics for metallization and contact formation can significantly reduce the cost per watt of producing photovoltaic devices. Inks have been developed for various materials, such as Ag, Cu, Ni and Al, which can be used to inkjet print metallizations for various kinds of photovoltaic devices. Use of these inks results in metallization with resistivities close to those of bulk materials. By means of inkjet printing a metallization grid can be printed with better resolution, i.e. smaller lines, than screen-printing. Also inks have been developed to deposit transparent conductive oxide films by means of ultrasonic spraying.

Energy Procedia, 2011

In this article we describe the work carried out in order to optimize n-type silicon solar cell front contacts by reducing the contact and line resistances. Both front and back contacts were created by screenprinting of a metal paste followed by the contact firing. After firing the front contacts were improved by electrolytic deposition of silver using a non-cyanide silver solution. In this work we used two different types of silicon wafers: electronic grade (EG-Si) and metallurgical grade (MG-Si). Two different solar cells processes were tested. The solar cells obtained where characterized before and after the plating step. For all the cells processed, the line resistance was reduced by over 85% after the silver deposition. After the contact improvement, EG-Si cells showed absolute efficiency improvements of the order of 3%, while MG-Si registered a minor efficiency improvement.

1977

This report was prepared as an account of work sponsored 6y the United States Government. Neither the United States nof. the United States Energy Research and Development Administration, nor any of their employees, ' nor any of their contractors; subcontractors, or their .employees, makes any ' warranty, express or implied, or assumes any Under the auspices of the liability or responsibility for the accuracy, completeness or usefulness of any information, app.8ratus, product or Division of Chemistry and Chemical Technology/ , process disciosed, or represents that its use would not Numerical Data Advisory Board/ National i infringe privately owned rights.

Progress in Photovoltaics Research and Applications, 1999

Consolidated tables showing an extensive listing of the highest independently con-®rmed eciencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July 1998 are brie¯y described. a CIGS CuInGaSe 2 ; a-Si amorphous silicon/hydrogen alloy. b Ec. eciency. c (ap) aperture area; (t) total area; (da) designated illumination area. d FF ®ll factor. Prog. Photovolt. Res. Appl. 7, 31±37 (1999) 32 M. A. GREEN ET AL. a CIGS CuInGaSe 2 . b Ec. eciency. c (ap) aperture area; (t) total area.

Progress in Photovoltaics: Research and Applications, 2020

In this work, we develop SiO x /poly-Si carrier-selective contacts grown by lowpressure chemical vapor deposition and boron or phosphorus doped by ion implantation. We investigate their passivation properties on symmetric structures while varying the thickness of poly-Si in a wide range (20-250 nm). Dose and energy of implantation as well as temperature and time of annealing were optimized, achieving implied open-circuit voltage well above 700 mV for electron-selective contacts regardless the poly-Si layer thickness. In case of hole-selective contacts, the passivation quality decreases by thinning the poly-Si layer. For both poly-Si doping types, forming gas annealing helps to augment the passivation quality. The optimized doped poly-Si layers are then implemented in c-Si solar cells featuring SiO 2 /poly-Si contacts with different polarities on both front and rear sides in a lean manufacturing process free from transparent conductive oxide (TCO). At cell level, open-circuit voltage degrades when thinner p-type poly-Si layer is employed, while a consistent gain in short circuit current is measured when front poly-Si thickness is thinned down from 250 to 35 nm (up to +4 mA/cm 2). We circumvent this limitation by decoupling front and rear layer thickness obtaining, on one hand, reasonably high current (J SC-EQE = 38.2 mA/cm 2) and, on the other hand, relatively high V OC of approximately 690 mV. The best TCO-free device using Ti-seeded Cu-plated front contact exhibits a fill factor of 75.2% and conversion efficiency of 19.6%.