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半導體物理 (二) 半導體之物理現象介紹.

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Presentation on theme: "半導體物理 (二) 半導體之物理現象介紹."— Presentation transcript:

1 半導體物理 (二) 半導體之物理現象介紹

2 半導體之物理現象介紹 Density of states function Fermi-Dirac distribution
Carrier concentrations Work function Excess carriers in semiconductors Diffusion of carriers Diffusion and drift of carriers

3 Density of states function & Fermi-Dirac distribution

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5 Carrier concentrations

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9 Work Function

10 Excess of carriers in semiconductors
If a carrier excess is created by optical excitation or carrier injection via a suitable contact. When the excitation is then suddenly cut off, the carrier concentrations will return gradually to their thermal equilibrium values owing to recombination of the excess carriers. Physically, t represents the average time an excess carrier remains free before recombining directly. The carrier lifetime for indirect recombination is more complicated than in the above case.

11 Diffusion of carriers

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13 Diffusion and drift of carriers


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