Methods of Forming Dopant-free, Asymmetric Heterocontact Structures

Tech ID: 25511 / UC Case 2016-050-0

Patent Status

Patent Pending

Brief Description

Worldwide photovoltaic capacity reached 178GW in 2014 and with an additional 55GW slated for deployment. With installed capacity projected to more than double by 2020, solar power is anticipated to become one of the largest sources of electricity, with solar photovoltaics representing about 16 percent of total. Current photovoltaic cell technology is based on crystalline silicon (c-Si) which generally uses doped homojunctions to create pathways of asymmetrical conductivity for electron and hole transport. This approach is limited by a host of interrelated optical, transport and recombination-based losses, most notably parasitic absorption and Auger recombination. Moreover, there are technological challenges and scaling problems associated with doping under high temperatures and with small contact fractions. To address these problems, researchers at the University of California, Berkeley, have developed advanced contact structures, which replace these doped regions, using alkali metal fluorides and metal oxides. Early lab results are reporting competitive cell efficiencies approaching 20%. These cells were fabricated using low-temperatures and no lithography, introducing potential for gains on both sides of the cost-to-performance ratio for c-Si photovoltaics.

Suggested uses

  • Solar cell design and manufacturing


  • Low temperature processing (less than 200 degrees Celsius)
  • Simpler architectures with minimal, lower-cost processing steps
  • Lithography-free processing for dopant-free heterocontacts

Related Materials


Learn About UC TechAlerts - Save Searches and receive new technology matches


  • Javey, Ali

Other Information

Categorized As