Charge injection and trapping in silicon nanocrystals

The temperature dependence of the conduction mechanism in thin films of similar to 8 nm diameter silicon nanocrystals is investigated using Al/Si nanocrystal/p-Si/Al diodes. A film thickness of 300 nm is used. From 300 to 200 K, space charge limited current, in the presence of an exponential distribution of trapping states, dominates the conduction mechanism. Using this model, a trap density N-t=2.3x10(17) cm(-3) and a characteristic trap temperature T-t=1670 K can be extracted. The trap density is within an order of magnitude of the nanocrystal number density, suggesting that most nanocrystals trap single or a few carriers at most. (C) 2005 American Institute of Physics.