Materials Research (Oct 2002)
Homogeneous Gaussian Profile P+-Type Emitters: Updated Parameters and Metal-Grid Optimization
Abstract
P+-type emitters were optimized keeping the base parameters constant. Updated internal parameters were considered. The surface recombination velocity was considered variable with the surface doping level. Passivated homogeneous emitters were found to have low emitter recombination density and high collection efficiency. A complete structure p+nn+ was analyzed, taking into account optimized shadowing and metal-contacted factors for laboratory cells as function of the surface doping level and the emitter thickness. The base parameters were kept constant to make the emitter characteristics evident. The most efficient P+-type passivated homogeneous emitters, provide efficiencies around 21% for a wide range of emitter sheet resistivity (50 -- 500 omega/) with the surface doping levels Ns=1×10(19) cm-3 and 5×10(19) cm-3. The output electrical parameters were evaluated considering the recently proposed value n i=9.65×10(9) (cm-3). A non-significant increase of 0.1% in the efficiency was obtained, validating all the conclusions obtained in this work, considering n i=1×10(10) cm-3.
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