Question

Charge density as a function of position is constant across a p-n junction

Answer 1

Charge density as a function of position is constant across the PN junction is a True Statement. Because P-N Junction has positive and negative charge. These positive and negative charges are both equal in depletion layer. It is also assumed that there is no free carriers in depletion region. So due to this phenomenon of charges density across P-N Junction is constant.

Answer 2

answer : true,

explanation : charge density as a function of position is given by, $\rho=(p-n+N^+_d-N^-_a)\cong q(N^+_d-N^-_a)$

where it is assumed that no free carriers are present within the depletion region. For an abrupt p-n diode with doping densities, Na and Nd, the charge density is then given by:

$\rho(x)=0\\\\\rho(x)=-qN_a\\\\\rho(x)=qN_d\\\\\rho(x)=0$

see graph, here it is clear that, Charge density as a function of position is constant across a p-n junction.