Complex representations of the group $GL(2,Z/p^nZ)$

We obtain a description of all irreducible complex representations of the group indicated in the title ($p\ne2$ is a prime). Namely, for each $n\geqslant2$ we distinguish three series of representations of degrees $(p+I)p^{n-1}$, $(p^2-I)p^{n-2}$, $(p-I)p^{n-1}$. The other representations of $GL(2,Z_{p^n})$ are obtained from representations of $GL(2,Z_{p^{n-1}})$ by tensor multiplication by one-dimensional representations.