Research

Research Interest

  1. Design, Modeling, Fabrication, Characterization and Analysis of Solar Cells
  2. Surface Passivation of Electron Devices
  3. III-V Solar cells and Opto-Electronic Devices
  4. Electrochemistry and Device Physics

Research Accomplishment

Inkjet printing technology

  •  Fabricated manufacturable ink jetted full gridline contacts solar cells with 18.5% efficiency
  • Fabricated manufacturable inkjetted seed and plated contact solar cells with record 18.7% efficiency

  Screen printing Technology

  • Understanding of contact formation to different emitters. Screen-printed contact to manufacturable homogeneous high sheet resistance (80 ops) emitter with efficiency of 17.8%.
  • Fabricated record high 18.8% efficient manufacturable silicon solar cell on 1-ohm-cm and textured float zoned Si using conventional furnace emitter.
  • Fabricated PERC structure with 20.5% efficiency
  • Fabricated record high 17.5% efficient manufacturable silicon solar cell on 0.6-ohm-cm and planar float zoned Si using conventional furnace emitter.
  • Fabricated record high 17.3% efficient manufacturable silicon solar cell on magnetically grown CZ Si.
    Fabricated record high 17% efficient manufacturable silicon solar cell on 1-ohm-cm and planar float zoned Si using infrared belt furnace emitter.
  • Fabricated ∼15% efficient belt line cell on cast multi-crystalline silicon with high fill factor using infrared belt furnace emitter and screen printed contacts
  • Fabricated record high >14% efficient cell on 100 µm thick dendritic web using a simplified manufacturable processing in conjunction with the screen-printing metallization scheme.

Buried Contact Technology

  • Fabrication of buried contact solar cells (BCSC) using laser, photolithography and mechanical means for groove formation. Fabrication of 18%, 49 cm2 cell on CZ Si.
  • Development of process sequence for double-sided buried contact (DSBC) solar cells, which was licensed to Samsung Electronics for commercial production. Fabrication of 18% 49 cm2 and 19% 4cm2 cells on FZ Si. 671 mV DSBC cell, which was the highest at the time.
  • Development of low temperature process sequence for CZ wafer processing
  • Development of process sequence for simultaneous diffusion of boron and phosphorus. Fabrication of 15% 4cm2 DSBC cells.
  • Fabrication of DSBC using laser, photolithography and mechanical means for groove formation. Use of vacuum evaporator for Al, Pd, Ti and Ag rear and front metal contacts. Electroless nickel and copper plating of groves. Silver electroplating and immersion silver. Mask aligner, elipsometer, four- point probe, tube furnaces and rapid thermal annealer.
  • Development of low cost process sequence using laser beam for dopant drive-in and fabrication of 13%, 49 cm2 BCSC on CZ.
  • Pilot Production of BCSC, PERL and Hybrid Cells.

 Other Solar Cell Technologies and Structures

  • PERL (passivated emitter and rear locally diffused) cell – full processing, which involves photolithography with 6 masking steps, evaporation of different metals, lift off process and electroplating.
  • PERL/BCSC hybrid – full photolithography process
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