The Hong Kong University of Science and Technology

Zhiguo Meng

Hoi Sing Kwok

Man Yu Wong

Man Chit Wong

Xiuling Zhu

Jiaxin Sun

Hoi-Sing Kwok

Shuyun Zhao

Dongli Zhang

Chunya Wu

Xuejie Shi

Mingxiang Wang

Tianfu Ma

A solar cell photovoltaic device using ultrathin films of polycrystalline silicon and deep uneven surface structures is disclosed. According to one embodiment, the uneven structures include one or more pits having a depth of at least 10 microns. According to another embodiment, the uneven structures include one or more cones or columns having a height or at least 10 microns. Because the unevenness of the structures, the photovoltaic device is able to use a very thin layer of polycrystalline silicon to effectively trap and absorb light.

Ultrathin film multi-crystalline photovoltaic device

The present invention provides a method of an active-matrix thin film transistor array, comprising of two levels of metallic interconnections formed from one layer of metallic conductor; and thin-film transistors with source, drain and gate electrodes either fully or partially replaced with metal, and wherein the pixel electrodes are polycrystalline silicon.

Method for fabrication of active-matrix display panels

A low temperature polycrystalline silicon device and techniques to manufacture thereof with excellent performance. Employing doped poly-Si lines which we called a bridged-grain structure (BG), the intrinsic or lightly doped channel is separated into multiple regions. A single gate covering the entire active channel including the doped lines is still used to control the current flow. Using this BG poly-Si as an active layer and making sure the TFT is designed so that the current flows perpendicularly to the parallel lines of grains, grain boundary effects can be reduced.

Polycrystalline silicon thin film transistors with bridged-grain structures

The invention provides a method for forming thin film transistors including a polycrystalline semiconducting film. The method comprises depositing a first layer of amorphous semiconducting thin film on to a substrate; depositing a second layer of thin film on to the first layer of amorphous semiconducting thin film; patterning the second layer of thin film so that the first layer of amorphous semiconducting thin film is exposed at selected locations; exposing the first and second layers of thin film to a nickel containing compound in either a solution or a vapor phase ; removing the second layer of thin film; and annealing the first layer of amorphous semiconducting thin film at an elevated temperature so the first layer of amorphous semiconducting thin film converts into a polycrystalline semiconducting thin film.

Metal-induced crystallization of amorphous silicon in thin film transistors

Metal induced polycrystallized silicon is used as the anode in a light emitting device, such as an OLED or AMOLED. The polycrystallized silicon is sufficiently non-absorptive, transparent and made sufficiently conductive for this purpose. A thin film transistor can be formed onto the polycrystallized silicon anode, with the silicon anode acting as the drain of the thin film transistor, thereby simplifying production.

Polycrystalline silicon as an electrode for a light emitting diode and method of making the same

An organic light-emitting diode display which can display independent images on both sides is described. This display can be driven with passive matrix or active matrix schemes. The invention combines a unique stacked organic diode structure and special driving schemes involving time-sequential reversed fields.

Double sided emission organic light emitting diode display

Crystallization-inducing metal elements are introduced onto an amorphous silicon thin film. A first, low-temperature, heat-treatment induces nucleation of metal-induced crystallization (MIC), resulting in the formation of small polycrystalline silicon 'islands'. A metal-gettering layer is formed on the resulting partially crystallized thin film. A second, low-temperature, heat-treatment completes the MIC process, whilst gettering metal elements from the partially crystallized thin film. The process results in the desired polycrystalline silicon thin film.

Metal-induced crystallization of amorphous silicon, polycrystalline silicon thin films produced thereby and thin film transistors produced therefrom

The construction of electrodes for liquid-crystal displays using larger grain lower absorption (LGLA) poly-Si showing an absorptivity below 20% in the visible light region is described. Integration in the manufacturing of substrates for active-matrix LCDs is shown. Source, drain and channel region () of the TFTs as well as the pixel-electrode () are formed conjointly in a single poly-Si layer.

Transflective liquid crystal device and method of manufacturing the same

The invention provides a method for forming thin film transistors including a polycrystalline semiconducting film. The method comprises depositing a first layer of amorphous semiconducting thin film on to a substrate; depositing a second layer of thin film on to the first layer of amorphous semiconducting thin film; patterning the second layer of thin film so that the first layer of amorphous semiconducting thin film is exposed at selected locations; exposing the first and second layers of thin film to a nickel containing compound in either a solution or a vapor phase; removing the second layer of thin film; and annealing the first layer of amorphous semiconducting thin film at an elevated temperature so the first layer of amorphous semiconducting thin film converts into a polycrystalline semiconducting thin film.

The invention provides a method of forming polycrystalline silicon comprising the steps of: forming a layer of amorphous silicon, forming a layer of metal or metal-containing compound on the layer of amorphous silicon, annealing the layer of amorphous silicon and said layer of metal to form a polycrystalline silicon layer, and irradiating the polycrystalline silicon layer with two different harmonics of a pulsed laser. The pulsed laser is preferably a solid-state laser such as a Nd-Yag laser. One harmonic is chosen such that it is preferentially absorbed by defects in the polycrystalline silicon layer, the other harmonic is absorbed by the bulk polycrystalline silicon.

Method of annealing polycrystalline silicon using solid-state laser and devices built thereon

A metal induced lateral crystallization (MILC) poly-silicon material is produced by depositing a metal in a predefined pattern on amorphous silicon, and heat treating the silicon at a first temperature to form a MILC poly-Si material. The MILC poly-Si material is further heat treated at a second temperature higher than the first temperature to induce recrystallization. The second high temperature recrystallization step significantly enhances the material structure, and in particular the grain structure, of the poly-Si material with substantial benefits to the performance of semiconductor devices made therefrom.

Polysilicon material and semiconductor devices formed therefrom

The present invention provides a method for forming metal-induced laterally crystallized polysilicon in which the metal residue is reduced. A first low temperature lateral crystallization is performed using a metal crystallization-inducing agent such as nickel or a nickel compound. A second lateral crystallization is then carried out which may be either a low-temperature crystallization using metal residue from the first crystallization as the metal crystallization-inducing agent, or may be a high temperature crystallization that does not require a metal.

Growing community of inventors

Hong Kong, China

Zhiguo Meng