A column VI impurity eg S that substitutes for a V atom in a

A column VI impurity (e.g., S) that substitutes for a V atom in a III-V semiconductor (e.g., for As in GaAs) will behave as...(Explain your answer) A. a donor. B. an acceptor. C. a neutral center. D. none of the above.

Solution

acts like a donor (n-type) because VI impuriy will have VI electrons(valancy) and V group atom will have V valancy electrons. out of VI impurites valancy electrons V valancy electrons will form covalent bond with V valancy electrons of V group atom remaining 1 electron free so each VI group impurity will give one free electron that is the reason this semiconducting material will acts as donar(n-type).