Disclosed is a plurality of metal chalcogenide nanocrystals coated with multiple organic and inorganic ligands; wherein the metal is selected from Hg, Pb, Sn, Cd, Bi, Sb or a mixture thereof; and the chalcogen is selected from S, Se, Te or a mixture thereof; wherein the multiple inorganic ligands includes at least one inorganic ligands are selected from S.sup.2, HS.sup., Se.sup.2, Te.sup.2, OH.sup., BF.sub.4.sup., PF.sub.6.sup., Cl.sup., Br.sup., I.sup., As.sub.2Se.sub.3, Sb.sub.2S.sub.3, Sb.sub.2Te.sub.3, Sb.sub.2Se.sub.3, As.sub.2S.sub.3 or a mixture thereof; and wherein the absorption of the CH bonds of the organic ligands relative to the absorption of metal chalcogenide nanocrystals is lower than 50%, preferably lower than 20%.

A photoresistor comprises two electrodes connected by a photosensitive layer of the photoresistor, and at least one additional layer which is in contact with the photosensitive layer in order to influence the behavior of the photoresistor regarding carrier collection between the two electrodes, in order to improve the sensitivity of the photoresistor.

A graphene nanostructure has a nanographene, a conjugated functional group bonded to the nanographene via a pyrazine skeleton, and at least one Br group and/or at least one CN group introduced into the conjugated functional group. A graphene nanostructure preferably has an average size of 1 nm or larger to 100 nm or smaller, a band gap of 0.01 eV or higher to 1.2 eV or lower, and/or a HOMO level of 6.0 eV or higher to 4.0 eV or lower. As the conjugated functional group into which the Br group(s) and/or the CN group(s) are/is introduced, a 4-bromobenzene group, a 4,5-dibromobenzene group, a 5-bromopyridine group, a 5-bromopyrazine group, a benzonitrile group, a phthalonitrile group, or a 2,3-dicyanopyrazine group is desirable.

A photosensitive field-effect transistor which can be configured to provide an electrical response when illuminated by electromagnetic radiation incident on the transistor. The field-effect transistor has a channel (13) made from a two-dimensional material and comprises a photoactive layer (22) which can be configured to donate charge carriers to the transistor channel (13) when electromagnetic radiation is absorbed in the photoactive layer (22). The photosensitive field-effect transistor comprises a top electrode (21) which is in contact with the photoactive layer on one or more contact areas which together form a contact pattern. With a suitably patterned top electrode (21), a voltage applied to the electrode can function as an electrical shutter which can switch the photosensitive field-effect transistor between a light-sensitive state and a light-immune state.

An organic semiconductor detector for detecting radiation has an organic conducting active region, an output electrode and a field effect semiconductor device. The field effect semiconductor device has a biasing voltage electrode and a gate electrode. The organic conducting active region is connected on one side to the field effect semiconductor device and is connected on another side to the output electrode.

Graphene photodetectors capable of operating in the sub-bandgap region relative to the bandgap of semiconductor nanoparticles, as well as methods of manufacturing the same, are provided. A photodetector can include a layer of graphene, a layer of semiconductor nanoparticles, a dielectric layer, a supporting medium, and a packaging layer. The semiconductor nanoparticles can be semiconductors with bandgaps larger than the energy of photons meant to be detected.

Techniques for growing, at least one of: (a) quantum dots and (b) nano-crystals, on a surface of a material are provided. One method comprises placing a precursor on the surface; adding an antisolvent to the precursor; and growing at least one of the quantum dots and the nanocrystals on the surface.

A photoelectric conversion device includes a first electrode and a second electrode facing each other, a photoelectric conversion layer between the first electrode and the second electrode and configured to absorb light in at least one part of a wavelength spectrum of light and to convert it into an electric signal, and an inorganic nanolayer between the first electrode and the photoelectric conversion layer and including a lanthanide element, calcium (Ca), potassium (K), aluminum (Al), or an alloy thereof. An organic CMOS image sensor may include the photoelectric conversion device. An electronic device may include the organic CMOS image sensor.

A photosensitive field-effect transistor comprising a substrate with a source electrode, a drain electrode and a gate electrode. The transistor comprises a photoactive layer which at least partly covers the gate electrode, and a channel layer which covers the photoactive layer and at least partly covers both the source electrode and the drain electrode. The channel layer comprises a two-dimensional material whose conductivity is modulated by charge carriers transferred from the photoactive layer when electromagnetic radiation is absorbed in the photoactive layer.

A light detector includes a semiconductor element, a first electrode, a second electrode and a current detecting element electrically connected with each other to form a circuit. The semiconductor element includes a semiconductor structure, a carbon nanotube and a transparent conductive film. The semiconductor structure includes a P-type semiconductor layer and an N-type semiconductor layer and defines a first surface and a second surface. The carbon nanotube is located on the first surface of the semiconductor. The transparent conductive film is located on the second surface of the semiconductor. The transparent conductive film is formed on the second surface by a depositing method or a coating method.