A photodetector having a small form factor and having high detection efficiency with respect to both visible light and infrared rays may include a first electrode, a collector layer on the first electrode, a tunnel barrier layer on the collector layer, a graphene layer on the tunnel barrier layer, an emitter layer on the graphene layer, and a second electrode on the emitter layer. The photodetector may be included in an image sensor. An image sensor may include a substrate, an insulating layer on the substrate, and a plurality of photodetectors on the insulating layer. The photodetectors may be aligned with each other in a direction extending parallel or perpendicular to a top surface of the insulating layer. The photodetector may be included in a LiDAR system.

A quantum well device includes a first layer of a first two-dimensional material, a second layer of a second two-dimensional material, and a third layer of a third two-dimensional material disposed between the first layer and second layer. The first layer, the second layer, and the third layer are adhered predominantly by van der Waals force.

Disclosed are a single-source precursor for synthesizing metal chalcogenide nanoparticles for producing a light absorption layer of solar cells comprising a Group VI element linked as a ligand to any one metal selected from the group consisting of copper (Cu), zinc (Zn) and tin (Sn), metal chalcogenide nanoparticles produced by heat-treating at least one type of the single-source precursor, a method of preparing the same, a thin film produced using the same and a method of producing the thin film.

A method for post-treating an absorber layer for photoelectric conversion of incident light into electric current. The method includes providing a chalcogen-containing absorber layer on a carrier, applying a post-treatment layer on a surface of the absorber layer, wherein the post-treatment material is not a buffer or component of a buffer, and thermally diffusing the post-treatment material into the absorber layer. A method for producing a layer system for the production of thin-film solar cells is also described.

Disclosed is a quantum dot based solar cell device which includes a substrate, a light harvesting structure sandwiched between electrically conducing layers, with at least one electrically conducting layer being substantially transparent with the light harvesting structure being located on the substrate. The light harvesting structure includes a layer of semiconducting quantum dots, with this layer of semiconducting quantum dots including at least two distinct sets of semiconducting quantum dots which are homogenously mixed. One of the two distinct sets of semiconducting quantum dots has a first bandgap and the at least one other distinct set of semiconducting quantum dots has a second bandgap different from the first bandgap. Both sets of semiconducting quantum dots are passivated with any one or combination of halides and pseudo-halides. Upon illumination, the quantum dot solar cell device exhibits a photovoltage that is intermediate between a photovoltage that would generated separately if the solar cell device had only the first set of quantum dots and a photovoltage that would be generated separately if the solar cell device had only the second set of quantum dots.

A composite material is described. The composite material comprises semiconductor nanocrystals, and organic molecules that passivate the surfaces of the semiconductor nanocrystals. One or more properties of the organic molecules facilitate the transfer of charge between the semiconductor nanocrystals. A semiconductor material is described that comprises p-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of electrons in the semiconductor material being greater than or equal to a mobility of holes. A semiconductor material is described that comprises n-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of holes in the semiconductor material being greater than or equal to a mobility of electrons.

PbO-based photoconductive X-ray imaging devices are disclosed in which the PbO photoconductive layer exhibits an amorphous crystal structure. According to selected embodiments, the amorphous PbO photoconductive layer may be formed by providing a substrate inside an evacuated evaporation chamber and evaporating lead oxide to deposit a photoconductive lead oxide layer onto the substrate, while subjecting the photoconductive layer to ion bombardment with oxygen ions having an ion energy between 25 and 100 eV. X-ray direct detection imaging devices formed from such amorphous PbO photoconductive layers are shown to exhibit image lag that is suitable for fluoroscopic imaging.

Example embodiments relate to optoelectronic devices. An optoelectronic device may include a photoactive layer between first and second electrodes, and a ferroelectric layer corresponding to at least one of the first and second electrodes. At least one of the first and second electrodes may include graphene. The photoactive layer may include a two-dimensional (2D) semiconductor. The optoelectronic device may further include a third electrode, and in this case, the ferroelectric layer may be between the second electrode and the third electrode. The second electrode, the ferroelectric layer, and the third electrode may constitute a nanogenerator.

Embodiments are directed to a chalcogenide material-based filterless color image sensor, which includes a substrate, a first chalcogenide material layer formed on a substrate for a first color, a second chalcogenide material layer formed on the first chalcogenide material layer for a second color, and a third chalcogenide material layer formed on the second chalcogenide material layer for a third color.

This invention includes multiple quantum well and quantum dot channel FETs, which can process multi-state/multi-bit logic, and multibit-bit inverters configured as static random-access memories (SRAMs). SRAMs can be implemented as flip-flops and registers. In addition, multiple quantum well and quantum dot channel structures are configured to function as multi-bit high-speed quantum dot (QD) random access memories (NVRAMs). Multi-bit Logic, SRAMs and QD-NVRAMs are spatially located on a chip, depending on the application, to provide a low-power consumption and high-speed hardware platform. The multi-bit logic, SRAM and register, and QD-NVRAM are implemented on a single chip in a CMOS-like platform for applications including artificial intelligence (AI) and machine learning.