Abstract
For glow-discharge a-Ge:H doped with phosphorus and boron the temperature dependence of conductivity and thermoelectric power has been investigated. For both dopants a maximum shift of the Fermi energy EF to the mobility edges of about 0.3 eV is obtained. The difference of the conductivity and thermoelectric power activation energies EQ = Eδ-Es lies around 0.16 eV and varies only little with doping; it rises somewhat by hydrogen effusion at temperatures above 300°C. The spin density of undoped a-Ge:H is approximately two orders of magnitude larger than for a-Si:H;it increases by irradiation with 3 MeV electrons and by hydrogen effusion by a factor of 4-5. Annealing at temperatures above 300°C leads to a positive sign of the thermoelectric power indicating that defect states created by hydrogen effusion pull the Fermi level below midgap.
Original language | English |
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Pages (from-to) | 319-330 |
Number of pages | 12 |
Journal | Solar Energy Materials |
Volume | 8 |
Issue number | 1-3 |
DOIs | |
State | Published - Nov 1982 |
Externally published | Yes |