Described herein is an optical sensor, a detector including the optical sensor for an optical detection of at least one object, a method for manufacturing the optical sensor and various uses of the optical detector. The optical sensor can be supplied as a non-bulky hermetic package which provides an increased degree of protection against possible degradation by humidity and/or oxygen over long terms. Further, the optical sensor may be easily manufactured and integrated on a circuit carrier device.

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including CuZnSnS(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

Optically sensitive devices include a device comprising a first contact and a second contact, each having a work function, and an optically sensitive material between the first contact and the second contact. The optically sensitive material comprises a p-type semiconductor, and the optically sensitive material has a work function. Circuitry applies a bias voltage between the first contact and the second contact. The optically sensitive material has an electron lifetime that is greater than the electron transit time from the first contact to the second contact when the bias is applied between the first contact and the second contact. The first contact provides injection of electrons and blocking the extraction of holes. The interface between the first contact and the optically sensitive material provides a surface recombination velocity less than 1 cm/s.

A photoelectric conversion device includes an electrode layer, a first semiconductor layer located on a main surface of the electrode layer, a plurality of insulating light scattering substances scattered in the first semiconductor layer or scattered at an interface between the first semiconductor layer and the electrode layer, and a second semiconductor layer making a pn junction with the first semiconductor layer on the first semiconductor layer to be located on an opposite side of the electrode layer.

There is provided a quantum dot solar cell having a high optical absorption coefficient. The quantum dot solar cell includes a quantum dot layer 3 including a plurality of quantum dots 1, wherein the quantum dot layer 3 includes a first quantum dot layer 3A having an index /x of 5% or more, wherein x is an average particle size, and is a standard deviation. The quantum dot layer 3 also includes a second quantum dot layer 3B that is provided on the light entrance surface 3b and/or the light exit surface 3c of the first quantum dot layer 3A and has an average particle size and an index /x smaller than those of the first quantum dot layer 3A.

A thin film of metal oxide includes zinc (Zn); tin (Sn); silicon (Si); and oxygen (O). In terms of oxide, based on 100 mol % of total of oxides of the thin film, SnO.sub.2 is greater than 15 mol % but less than or equal to 95 mol %.

Optically sensitive devices include a device comprising a first contact and a second contact, each having a work function, and an optically sensitive material between the first contact and the second contact. The optically sensitive material comprises a p-type semiconductor, and the optically sensitive material has a work function. Circuitry applies a bias voltage between the first contact and the second contact. The optically sensitive material has an electron lifetime that is greater than the electron transit time from the first contact to the second contact when the bias is applied between the first contact and the second contact. The first contact provides injection of electrons and blocking the extraction of holes. The interface between the first contact and the optically sensitive material provides a surface recombination velocity less than 1 cm/s.

An arrangement for a thin-film photovoltaic cell stack comprises a substrate layer for a photovoltaic cell and a molybdenum grid positioned on the substrate layer, an ultra-thin alloy layer made of copper, indium, gallium and selenium positioned on the molybdenum grid, and a buffer layer positioned on the ultra-thin alloy layer made of copper, indium, gallium and selenium and a window layer positioned on the buffer layer.

Disclosed are a double-sided solar cell and a preparation method therefor. The double-sided solar cell comprises: a silicon wafer having a PN junction, and a front first silicon oxide layer, a front second silicon oxide layer, a front first nitrogen-containing silicon compound layer, a front second nitrogen-containing silicon compound layer, and a front third silicon oxide layer that are located on one side of an N-type layer of the silicon wafer and are sequentially stacked along a direction away from the silicon wafer; and a passivation layer, a back silicon oxide layer, a back first nitrogen-containing silicon compound layer, and a back second nitrogen-containing silicon compound layer that are located on one side of a P-type layer of the silicon wafer and are sequentially stacked along the direction away from the silicon wafer.

Methods and systems are provided for a photoconductive thin film of a plurality of Lead Selenide (PbSe) nanostructures arranged on quartz substrates. The photoconductive thin film is synthesized, for example, using a chemical bath deposition, and can include a tunable iodine doping process to select the size and/or shape of the nanostructures. An oxygenation sensitization process at a sufficiently high temperature can increase carrier mobility of the thin film.