Germanium and Silicon Nanocrystal Thin-Film Field-Effect Transistors from Solution

Germanium and silicon have lagged behind more popular II-VI and IV-VI semiconductor materials in the emerging field of semiconductor nanocrystal thin film devices. We report germanium and silicon nanocrystal field-effect transistors fabricated by synthesizing nanocrystals in a plasma, transferring them into solution, and casting thin films. Germanium devices show n-type, ambipolar, or p-type behavior depending on annealing temperature with electron and hole mobilities as large as 0.02 and 0.006 cm(2) V(-1) s(-1), respectively. Silicon devices exhibit n-type behavior without any postdeposition treatment, but are plagued by poor film morphology.