Unformatted text preview: 1 A numerical example Identify each curve with a region of the solar cell. 2 The world record holder • Why is the front surface textured? • Why is there a thin oxide over most of the front and the back? 3 PV power Sections 7.5, 7.6, 7.7 of course text: 1. 2. 3. Photovoltaic power Non-silicon solar cells Photovoltaics for terrestrial power generation 4 Generating a voltage Jph How does the voltage generated across the resistor bias the diode ? 5 Photovoltage + RLoad Iphoto - • Connect load • Voltage across the load forward biases the diode • Dark current opposes Iphoto
Idark RLoad IL < Iphoto Iphoto - 6 Superposition
I Voc Iphoto V What is the expression for Voc ? 7 PV Power What is FF ? 8 PV efficiency • Why does efficiency vary with bandgap? • Why are >90% of the world's solar cells made from Si rather than GaAs? 9 Multi-crystalline Sii alternative crystalline S 10 Thin-film solar cell 11 Multijunction solar cell 12 Problem with matching multi-junction cells What happens if JPh,1 > JPh,2 ? 13 Obstacles to PV power implementation Diurnal and seasonal variation Storage 14 The competition or the complement? ...
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- Fall '09
- Photovoltaics, Solar cell, solar cells, PV Power, current opposes Iphoto