Certain embodiments of the present invention may be directed to a transistor structure. The transistor structure may include a semiconductor substrate. The semiconductor substrate may include a drift region, a collector region, an emitter region, and a lightly-doped/undoped region. The lightly-doped/undoped region may be lightly-doped and/or undoped. The transistor structure may also include a heterostructure. The heterostructure forms a heterojunction with the lightly-doped/undoped region. The transistor structure may also include a collector terminal. The collector terminal is in contact with the collector region. The transistor structure may also include a gate terminal. The gate terminal is in contact with the heterostructure. The transistor structure may also include an emitter terminal. The emitter terminal is in contact with the lightly-doped/undoped region and the emitter region.

Provided are an atomic layer junction oxide, a method of preparing the atomic layer junction oxide, and a photoelectric conversion device including the atomic layer junction oxide. The atomic layer junction oxide can include an n-type doped atomic layer oxide; an intrinsic atomic layer oxide; a p-type doped atomic layer oxide; and an intrinsic atomic layer oxide.

A superlattice and method for forming that superlattice are disclosed. In particular, an engineered layered single crystal structure forming a superlattice is disclosed. The superlattice provides p-type or n-type conductivity, and comprises alternating host layers and impurity layers, wherein: the host layers consist essentially of a semiconductor material; and the impurity layers consist of a donor or acceptor material.

A method produces a light-receiving device by growing a light-receiving layer having an undoped multi-quantum well structure; growing a cap layer on the light-receiving layer while the cap layer is doped with a p-type impurity during its growth; growing a mesa structure; growing a protective film on surfaces of the mesa structure; and annealing to form a p-n junction. The mesa structure is defined by a surrounding trench. Alternatively, a selective growth mask can be formed on the light-receiving layer whereafter the cap layer is grown on the light-receiving layer by use of the mask. In the alternative, the p-n junction is formed by diffusing p-type impurity from a p-type contact layer of the cap layer through a concentration adjusting layer thereof to the light-receiving layer.

Materials and methods may be provided for short-wave infrared (SWIR) superlattice materials. The superlattice material includes a first sub-layer comprising InAs, and a second sub-layer adjacent to the first sub-layer including AlSb, AlAsSb, or InAlAsSb.

A superlattice and method for forming that superlattice are disclosed. In particular, an engineered layered single crystal structure forming a superlattice is disclosed. The superlattice provides p-type or n-type conductivity, and comprises alternating host layers and impurity layers, wherein: the host layers consist essentially of a semiconductor material; and the impurity layers consist essentially of a corresponding donor or acceptor material.

Embodiments of the present disclosure are directed to infrared detector devices incorporating a tunneling structure. In one embodiment, an infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a tunneling structure including a barrier layer adjacent to the absorber layer and a second contact layer adjacent to the barrier layer. The barrier layer has a tailored valence band offset such that a valence band offset of the barrier layer at the interface between the absorber layer and the barrier layer is substantially aligned with the valence band offset of the absorber layer, and the valence band offset of the barrier layer at the interface between the barrier layer and the second contact layer is above a conduction band offset of the second contact layer.

Material and antireflection structure and methods of manufacturing are provided that produce efficient photovoltaic power conversion from thin film solar cells on flexible substrates. Step-graded antireflection structures are placed on the front of the device structure. Materials of different energy gap are combined in the depletion region of at least one of the semiconductor junctions within the thin film device structure. Conductive, low refractive index layers are deposited on the bottom of the thin film device structure to form an omni-directional back reflector contact.

A photoelectric conversion element according to the present invention includes a photoelectric conversion layer. The photoelectric conversion layer includes a p-type semiconductor layer, an n-type semiconductor layer, and a superlattice semiconductor layer which is interposed between the p-type semiconductor layer and the n-type semiconductor layer. The superlattice semiconductor layer has a superlattice structure in which barrier layers and quantum layers are stacked alternately and repeatedly, and is provided so as to form an intermediate energy band between an upper end of a valence band of the barrier layer and a lower end of a conduction band of the barrier layer. The intermediate energy band is formed from a region of the superlattice semiconductor layer, which is near to the p-type semiconductor layer, to a region of the superlattice semiconductor layer, which is near to the n-type semiconductor layer, and the intermediate energy band has a region having a wide band width and a region having a narrow band width.

Provided are an atomic layer junction oxide, a method of preparing the atomic layer junction oxide, and a photoelectric conversion device including the atomic layer junction oxide.