High open circuit voltages on < 50 micron silicon substrates by amorphous-silicon (a-Si) and quinhydrone-methanol (QHY-ME) passivation

Bhumika Chhabra, Christiana Honsberg, Robert L. Opila

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Thin silicon solar cells offer the well-known advantages of cost reduction and higher efficiencies. A thinner solar cell may have a higher open circuit voltage than a thicker one assuming the surfaces are well passivated and the light trapping is included thus resulting in improved efficiencies. High open circuit voltage, Voc, of 720 mV [1] or above has been achieved from several technologies on conventional thickness wafers and has approached 740 mV on thinner wafers [2]. However, the theoretical limit from detailed balance calculations is between 830 mV and 850 mV (depending on spectrum) [3]. In order to achieve silicon solar cells which approach the detailed balance voltage limits, controlling the broad mechanisms that limit the open circuit voltage becomes very important and these are: (1) Auger recombination (e.g., by controlling dopant concentration); (2) the thickness of the material; and (3) the surface passivation. While high open circuit voltages have been demonstrated on thicker silicon solar cells, achieving the necessary surface passivation for "thin" solar cells (i.e., less than 50 micron thick wafers) to show increase in Voc has remained a challenge. The present research demonstrates via Implied-Voc measurements that amorphous-Si passivation as well as organic passivation based on quinhydrone-methanol has sufficient surface passivation such that open circuit voltage increases even at thickness of 35 microns. These results are also significant in demonstrating that non-ideal effects, such as high injection, play a significant role in determining Voc, but nevertheless experimentally still allow high open circuit voltages as the device is thinned.

Original languageEnglish (US)
Title of host publicationConference Record of the IEEE Photovoltaic Specialists Conference
Pages2187-2190
Number of pages4
DOIs
StatePublished - 2009
Event2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009 - Philadelphia, PA, United States
Duration: Jun 7 2009Jun 12 2009

Other

Other2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009
CountryUnited States
CityPhiladelphia, PA
Period6/7/096/12/09

Fingerprint

Open circuit voltage
Amorphous silicon
Passivation
Methanol
Silicon
Silicon solar cells
Substrates
Solar cells
Cost reduction
Doping (additives)
Electric potential

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering

Cite this

Chhabra, B., Honsberg, C., & Opila, R. L. (2009). High open circuit voltages on < 50 micron silicon substrates by amorphous-silicon (a-Si) and quinhydrone-methanol (QHY-ME) passivation. In Conference Record of the IEEE Photovoltaic Specialists Conference (pp. 2187-2190). [5411398] https://doi.org/10.1109/PVSC.2009.5411398

High open circuit voltages on < 50 micron silicon substrates by amorphous-silicon (a-Si) and quinhydrone-methanol (QHY-ME) passivation. / Chhabra, Bhumika; Honsberg, Christiana; Opila, Robert L.

Conference Record of the IEEE Photovoltaic Specialists Conference. 2009. p. 2187-2190 5411398.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Chhabra, B, Honsberg, C & Opila, RL 2009, High open circuit voltages on < 50 micron silicon substrates by amorphous-silicon (a-Si) and quinhydrone-methanol (QHY-ME) passivation. in Conference Record of the IEEE Photovoltaic Specialists Conference., 5411398, pp. 2187-2190, 2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009, Philadelphia, PA, United States, 6/7/09. https://doi.org/10.1109/PVSC.2009.5411398
Chhabra, Bhumika ; Honsberg, Christiana ; Opila, Robert L. / High open circuit voltages on < 50 micron silicon substrates by amorphous-silicon (a-Si) and quinhydrone-methanol (QHY-ME) passivation. Conference Record of the IEEE Photovoltaic Specialists Conference. 2009. pp. 2187-2190
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