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Title: Titanium dioxide/silicon hole-blocking selective contact to enable double-heterojunction crystalline silicon-based solar cell

In this work, we use an electron-selective titanium dioxide (TiO{sub 2}) heterojunction contact to silicon to block minority carrier holes in the silicon from recombining at the cathode contact of a silicon-based photovoltaic device. We present four pieces of evidence demonstrating the beneficial effect of adding the TiO{sub 2} hole-blocking layer: reduced dark current, increased open circuit voltage (V{sub OC}), increased quantum efficiency at longer wavelengths, and increased stored minority carrier charge under forward bias. The importance of a low rate of recombination of minority carriers at the Si/TiO{sub 2} interface for effective blocking of minority carriers is quantitatively described. The anode is made of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) heterojunction to silicon which forms a hole selective contact, so that the entire device is made at a maximum temperature of 100 °C, with no doping gradients or junctions in the silicon. A low rate of recombination of minority carriers at the Si/TiO{sub 2} interface is crucial for effective blocking of minority carriers. Such a pair of complementary carrier-selective heterojunctions offers a path towards high-efficiency silicon solar cells using relatively simple and near-room temperature fabrication techniques.
Authors:
; ; ; ; ; ;  [1] ;  [2] ;  [1] ; ;  [1] ;  [2]
  1. Princeton Institute for the Science and Technology of Materials (PRISM), Princeton, New Jersey 08544 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22398795
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANODES; CATHODES; CHANNELING; CHARGE CARRIERS; DEPLETION LAYER; ELECTRIC CONTACTS; ELECTRIC POTENTIAL; ELECTRONS; HETEROJUNCTIONS; HOLES; INTERFACES; PHOTOVOLTAIC EFFECT; QUANTUM EFFICIENCY; RECOMBINATION; SILICON; SILICON SOLAR CELLS; TEMPERATURE RANGE 0273-0400 K; TITANIUM OXIDES