Transport properties of semiconducting nanocrystal arrays at low temperatures

We study the electron transport in semiconducting nanocrystal arrays at temperatures $T\ll E_c$, where $E_c$ is the charging energy for a single grain. In this temperature range the electron transport is dominated by co-tunneling processes. We discuss both elastic and inelastic co-tunneling and show that for semiconducting nanocrystal arrays the inelastic contribution is strongly suppressed at low temperatures. We also compare our results with available experimental data.