Lai Jianjun

Fabrication and Characterization of Nanocrystalline VO2 Thin Films

Nanocrystalline VO2 films with phase transition temperature 34 degrees C have been fabricated on Si3N4-film-coated silicon and quartz substrates by argon-annealing films of metastable VO2(B). The original VO2(B) films are obtained by ion beam sputtering in an argon-oxygen atmosphere at 200 degrees C. The nanocrystalline VO2 films exhibit strong changes in electrical and optical properties when a phase transition is completed. The phase transition temperature in the as-fabricated samples is about 34 degrees C, which is smaller in comparison with 68 degrees C in the single-crystalline VO2 material. A lower phase transition temperature is favorable for device applications such as smart window coating and low power consumption optical switching.

Fabrication, Testing and Integration Technologies of Polymer Microlens for Pt/Si Schottky-Barrier Infrared Charge Coupled Device Applications

A novel polymer refractive microlens array has been formed on the surface of 256(V)×290(H) PtSi Schottky-barrier infrared charge coupled device (IRCCD) image sensors to improve the photoresponsivity of the IRCCD. The fabrication process flows of polymer microlens array are described. An effective aperture ratio in excess of 92% of microlens array has been achieved. An experimental facility to evaluate the optical performance of microlens array is introduced. The measurement results show that the microlens array indicates better than 4% non-uniformity of focal length and high optical performance. The application of the microlens array to improve the photosensitivity of infrared CCD is discussed.