Laser-induced self organization of silicon-germanium hillocks for field emission displays

We report here on the formation of a self-organized hillock structure in polycrystalline silicon-germanium (SiGe) thin films with a Ge content of 30 to 70%, due to the irradiation of the films with a sequence of laser pulses. By varying the crystallization parameters it is possible to control the periodicity length of the structure from 0.4 to 2 mu m. The self organization phenomenon can be switched on and off by using substrates with different thermal conductivities. In addition, we show that the self organized hillock structure exhibits a low field emission threshold of 20 V/mu m and therefore has an immense potential for field emission displays. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.