A method for manufacturing a novel semiconductor device is provided. The method includes a first step of forming a first oxide semiconductor film over a substrate, a second step of heating the first oxide semiconductor film, and a third step of forming a second oxide semiconductor film over the first oxide semiconductor film. The first to third steps are performed in an atmosphere in which water vapor partial pressure is lower than water vapor partial pressure in atmospheric air, and the first step, the second step, and the third step are successively performed in this order.

To provide a crystalline oxide semiconductor film, an ion is made to collide with a target including a crystalline In—Ga—Zn oxide, thereby separating a flat-plate-like In—Ga—Zn oxide in which a first layer including a gallium atom, a zinc atom, and an oxygen atom, a second layer including an indium atom and an oxygen atom, and a third layer including a gallium atom, a zinc atom, and an oxygen atom are stacked in this order; and the flat-plate-like In—Ga—Zn oxide is irregularly deposited over a substrate while the crystallinity is maintained.

There is provided a thin film manufacturing method which allows both a reduction in the carbon impurity concentration and a high film forming speed, as well as allows separate formation of stable crystal structures. There is provided a method for manufacturing an oxide crystal thin film. The method includes carrying raw material fine particles to a film forming chamber by means of a carrier gas, the raw material fine particles being formed from a raw material solution including water and at least one of a gallium compound and an indium compound, and forming an oxide crystal thin film on a sample on which films are to be formed, the sample being placed in the film forming chamber. At least one of the gallium compound and the indium compound is bromide or iodide.

The invention provides a suitable method and an appropriate, PV film structure. This aim is achieved by a room temperature method in which aqueous dispersions are printed onto a substrate and cured by an accompanying reaction. The accompanying reaction forms gradients and also nanoscale structures at the film boundaries, which produce a PV active film having standard performance and a higher stability. At around 10% efficiency, stability and no initial loss in performance in the climatic chamber test can be obtained and over a 20 year test period, consistently less fluctuation can be achieved. The method is free from tempering or sintering steps, enables the use of technically pure, advantageous starting materials and makes the PV film structure available as a finished, highly flexible cell for a fraction of the typical investment in production or distribution.

Embodiments of the invention provide a method of forming a group III-V material utilized in thin film transistor devices. In one embodiment, a gallium arsenide based (GaAs) layer with or without dopants formed from a solution based precursor may be utilized in thin film transistor devices. The gallium arsenide based (GaAs) layer formed from the solution based precursor may be incorporated in thin film transistor devices to improve device performance and device speed. In one embodiment, a thin film transistor structure includes a gate insulator layer disposed on a substrate, a GaAs based layer disposed over the gate insulator layer, and a source-drain metal electrode layer disposed adjacent to the GaAs based layer.

Methods of making a semiconductor layer from nanocrystals are disclosed. A film of nanocrystals capped with a ligand can be deposited onto a substrate; and the nanocrystals can be irradiated with one or more pulses of light. The pulsed light can be used to substantially remove the ligands from the nanocrystals and leave the nanocrystals unsintered or sintered, thereby providing a semiconductor layer. Layered structures comprising these semiconductor layers with an electrode are also disclosed. Devices comprising such layered structures are also disclosed.

A method for preparing semiconductor nanocrystals is disclosed. The method includes adding one or more cation precursors and one or more anion precursors in a reaction mixture including a solvent in a reaction vessel, maintaining the reaction mixture at a first temperature and for a first time period sufficient to produce semiconductor nanocrystal seed particles of the cation and the anion, and maintaining the reaction mixture at a second temperature that is higher than the first temperature for a second time period sufficient to enlarge the semiconductor nanocrystal seed particles to produce semiconductor nanocrystals from the cation and the anion.

A direct solution method based on a versatile amine-thiol solvent mixture which dissolves elemental metals, metal salts, organometallic complexes, metal chalcogenides, and metal oxides is described. The metal containing and metal chalcogenide precursors can be prepared by dissolving single or multiple metal sources, chalcogens, and/or metal chalcogenide compounds separately, simultaneously, or stepwise. Multinary metal chalcogenides containing at least one of copper, zinc, tin, indium, gallium, cadmium, germanium, and lead, with at least one of sulfur, selenium, or both are obtained from the above-mentioned metal chalcogenide precursors in the form of thin films, nanoparticles, inks, etc. Furthermore, infiltration of metal containing compounds into a porous structure can be achieved using the amine-thiol based precursors. In addition, due to the appreciable solubility of metal sources, metal chalcogenides, and metal oxides in the mixture of amine(s) and thiol(s), this solvent mixture can be used to remove these materials from a system.

Amorphous two-dimensional graphene-like carbon films provide benefits to a variety of applications due to advantageous electrical, mechanical, and chemical properties. Methods are provided to efficiently and cheaply create high-quality amorphous two-dimensional carbon films with embedded graphene-like nanocrystallites using coal as a precursor. These methods employ solution-phase deposition of coal-derived graphene-containing quantum dots followed by relatively low-temperature annealing/crosslinking of the quantum dots to form a single two-dimensional layer of carbon that includes a plurality of randomly-oriented discrete graphene domains connected to each other via amorphous carbon regions. Multi-layer films can be easily created by repeating the deposition and annealing processes. Two-dimensional carbon films formed in this manner exhibit improved properties when compared to crystalline graphene sheets and have properties especially suited to use as the storage medium of memristors. Further processing can result in large free-standing two-dimensional graphene-like carbon thin films that can be used as membranes or for other applications.

An anion exchange method using an anion exchange precursor based on a metal-chalcogenide compound is provided. The anion exchange method includes exchanging an anionic element of a nanoparticle with an element X of an anion exchange precursor represented by Na.sub.2X.sub.n via a reaction between the anion exchange precursor and the nanoparticle in the presence of a reaction medium, wherein X is at least one element selected from the group consisting of Se, S, and Te, and n is an integer from 2 to 10.