Abstract: Embodiments include photoactive regions of organic photovoltaic cells including an n-type dopant or a mixture of n-type dopants, one or more electron donor materials, and one or more electron acceptor materials. Embodiments further include n-type dopants, photoactive regions of organic photovoltaics comprising n-type dopants, methods of preparing photoactive regions comprising n-type dopants, organic photovoltaics comprising n-type doped photoactive regions, and the like.

Abstract: A thin-film field-effect transistor is formed by forming a dielectric layer adjacent a gate, forming a source region and a drain region, and forming a semiconductor layer on the dielectric layer. The semiconductor layer is deposited by spray pyrolysis and comprises a material selected from a group comprising: oxides; oxide-based materials; mixed oxides; metallic type oxides; group I-IV, II-VI, III-VI, IV-VI, V-VI and VIII-VI binary chalcogenides; and group I-II-VI, II-II-VI, II-III-VI, II-VI-VI and V-II-VI ternary chalcogenides.

Abstract: A low-voltage thin-film field-effect transistor is formed by forming a gate, forming a dielectric layer on the surface of the gate, forming a source region and a drain region, and forming a semiconductor layer adjacent the dielectric layer. The dielectric layer is formed as a native oxide layer by oxidizing the surface of the gate. The semiconductor layer is deposited by spray pyrolysis. The dielectric layer may be functionalized with a self-assembling monolayer dielectric layer. The dielectric layer may be formed as a self-assembling monolayer, without first forming a native oxide (or other) dielectric layer.

Abstract: An organic field-effect transistor comprising: a source region; a drain region; one or more organic semiconductor layers disposed between the source and drain regions; a gate region; and a dielectric region disposed between the organic semiconductor layer(s) and the gate region; wherein the composition of the organic semiconductor layer(s) is such as to transport both electrons and holes, with the mobility of the holes being substantially equal to the mobility of the electrons such that the transistor substantially exhibits ambipolarity in its transfer characteristics. The organic field-effect transistor is preferably a light-sensing organic field-effect transistor. Numerous modifications to the composition and structure of organic field-effect transistors are also disclosed, as are examples of electro-optical switches, electro-optical logic circuits and image sensing arrays.

Abstract: A field-effect transistor includes a source region; a drain region; a semiconductor layer disposed between the source and drain regions; a gate region; and a dielectric region disposed between the semiconductor layer and the gate region. The semiconductor layer comprises a titanium dioxide film. The transistor may be light sending, gas- or bio-sensing, or used in a visual display or in electronic circuits. The transistor is formed by forming a dielectric layer adjacent a gate region; forming a source region and a drain region; and forming a semiconductor layer on the dielectric layer, the semiconductor layer comprising titanium dioxide. The titanium dioxide semiconductor layer may be deposited by spray pyrolysis, or alternatively mesoporous TiO2 films of nanocrystalline morphology may be formed by spin coating, doctor-blading or screen-printing techniques.

Abstract: Provided is a filed-effect transistor with an organic semiconductor material showing ambipolar behaviour. Thereto, the organic semiconductor material enabling the ambipolar behaviour is a material with a small band gap.