Characterization for the Development of the Hybrid Multi-Junction Silicon Germanium Solar Cell
Technical Report,01 Sep 2014,24 Mar 2016
AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH WRIGHT-PATTERSON AFB United States
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Based on the previous development of the hybrid multi-junction silicon HMJ-Si solar cell, this work characterized the preceding design for the development of the hybrid multi-junction silicon germanium HMJ-SiGe solar cell architecture. Seven focus areas were investigated diffraction pattern generation, photon propagation, silicon diffusion processing, ohmic contacts, the distributed Bragg reflector DBR, the Fresnel zone plate FZP, and the germaniumgermanium telluride GeGeTe pn-junction. Generated diffraction patterns were theoretically examined, and contact grating design characterization for reflectance and transmittance properties was modeled using rigorous coupled wave analysis. An improved silicon diffusion process follower was developed, and theoretical study and experimental assessment was accomplished for appropriate ohmic contacts, the DBR, the FZP, and theGeGeTe pn-junction for incorporation into the new HMJ-SiGe solar cell architecture. Results showed that minima locations are nonexistent, the ratio between the metal width and electrical contact spacing is vital, an interfacial layer is required for de-pinning of the Fermi level, the DBR can reject detrimental wavelengths, the FZP excessively prevents transmittance, and p-type GeTe can form a pn-juncton on n-type germanium. With an average efficiency of 1.27 ,the HMJ-SiGe solar cell demonstrated a capstone requirement of charging a capacitor to 2.5VDC in 11 minutes to illuminate a light emitting diode.15.
- Solid State Physics
- Electric Power Production and Distribution