Chi-Chou Lin

Light emission from conductive paths in nanocrystalline CdSe embedded Zr-doped HfO2 high-k stack

Electrical and optical properties of the solid state incandescent light emitting devices made of zirconium doped hafnium oxide high-k films with and without an embedded nanocrystalline CdSe layer on the p-type Si wafer have been studied. The broad band white light was emitted from nano sized conductive paths through the thermal excitation mechanism. Conductive paths formed from the dielectric breakdown have been confirmed from scanning electron microscopic and atomic force microscopic images and the secondary ion mass spectrometric elemental profiles. Si was diffused from the wafer to the device surface through the conductive path during the high temperature light emission process. There are many potential applications of this type of device.

A solid-state incandescent device for single-chip white-light emission

Single-chip, white-light emitting devices made of sub 10 nm thick metal oxide dielectric films have been investigated for optical properties, operation principles, and reliability. Key elements for the light emission, lifetime, and efficiency are discussed.

Crystallization of a-Si thin film using an ultra thin n + poly-Si seed layer for solar cell applications

New results on the crystallization of the a-Si thin film using the low thermal budget pulsed rapid thermal annealing process and the SiO2 sacrificial layer are reported. The intrinsic a-Si thin film was transformed into the poly-Si thin film with a 30 nm thick n+ poly-Si seed layer. Process parameters, such as the number of the pulsed rapid thermal annealing cycles, affected the grain structure of the n+ film on the glass/Mo/Ni surface. Material properties, such as the crystal size and the volume fraction of the crystalline phase, of the intrinsic poly-Si thin films were influenced by the grain structure of the n+ seed layer. The multi-step pulsed rapid thermal annealing process can reduce the Ni residue in the crystallized Si film. Therefore, in addition to the thermal budget, the material property of the seed layer is critical to the final poly-Si properties. The poly-Si films structure and impurity content are important to the solar cell performance.