Pure Si at 500 K has equal number of electron (n_e) and hole (n_h) concentrations of 1.5 10^ 16 m ^ -3 . Doping by indium increases n_h to 4.5 10^ 22 m ^ -3 . The doped semiconductor is of :

NEET 2011 Physics question

Not in JEE Advanced syllabus

Pure Si at has equal number of electron () and hole () concentrations of . Doping by indium increases to . The doped semiconductor is of :

(1)n-type with electron concentration
(2)p-type with electron concentration
(3)n-type with electron concentration
(4)p-type having electron concentrations Correct

Answer: (4)

Solution

Indium is a trivalent (acceptor) impurity, so doping Si with indium creates holes: the semiconductor is p-type, which already eliminates (1) and (3). By the law of mass action, . With and $ = 4.5×\

See the full step-by-step solution

Create a free account to read the complete working, and practise questions like this in a timed test.

Create a free account

Question ID VK-090754