A system and method are presented for the design and fabrication of arrays of vacuum photodiodes for application to solar power generation. In a preferred embodiment, each photodiode cell comprises a microfabricated enclosure with a hermetically sealed vacuum, an absorptive photocathode, and a transparent anode, wherein the photocathode and the anode are separated by a vacuum gap of less than about 20 micrometers. Light incident on the photocathode through the anode leads to a flux of electrons passing from the photocathode across the vacuum gap to the anode. In a further preferred embodiment, the photocathode is backed by a reflection layer with, e.g., controlled diffuse reflection, thus increasing the efficiency of energy extraction. An array of such cells may be manufactured using automated thin-film deposition and micromachining techniques.

An emission enhancement structure having at least one energy augmentation structure; and an energy converter capable of receiving energy from an energy source, converting the energy and emitting therefrom a light of a different energy than the received energy. The energy converter is disposed in a vicinity of the at least one energy augmentation structure such that the emitted light is emitted with an intensity larger than if the converter were remote from the at least one energy augmentation structure. Also described are various uses for the energy emitters, energy augmentation structures and energy collectors in a wide array of fields, especially in the field of solar cells and other energy conversion devices.

An emission enhancement structure having at least one energy augmentation structure; and an energy converter capable of receiving energy from an energy source, converting the energy and emitting therefrom a light of a different energy than the received energy. The energy converter is disposed in a vicinity of the at least one energy augmentation structure such that the emitted light is emitted with an intensity larger than if the converter were remote from the at least one energy augmentation structure. Also described are various uses for the energy emitters, energy augmentation structures and energy collectors in a wide array of fields, especially in the field of solar cells and other energy conversion devices.

Monolithic tandem chalcopyrite-perovskite photovoltaic devices and techniques for formation thereof are provided. In one aspect, a tandem photovoltaic device is provided. The tandem photovoltaic device includes a substrate; a bottom solar cell on the substrate, the bottom solar cell having a first absorber layer that includes a chalcopyrite material; and a top solar cell monolithically integrated with the bottom solar cell, the top solar cell having a second absorber layer that includes a perovskite material. A monolithic tandem photovoltaic device and method of formation thereof are also provided.

Monolithic tandem chalcopyrite-perovskite photovoltaic devices and techniques for formation thereof are provided. In one aspect, a tandem photovoltaic device is provided. The tandem photovoltaic device includes a substrate; a bottom solar cell on the substrate, the bottom solar cell having a first absorber layer that includes a chalcopyrite material; and a top solar cell monolithically integrated with the bottom solar cell, the top solar cell having a second absorber layer that includes a perovskite material. A monolithic tandem photovoltaic device and method of formation thereof are also provided.

A multijunction tandem photovoltaic device is disclosed having a bottom subcell of silicon germanium or silicon germanium tin material and above that a subcell of gallium nitride arsenide bismide, or indium gallium nitride arsenide bismide, material. The materials are lattice matched to gallium arsenide, which preferably forms the substrate. Preferably, further lattice matched subcells of gallium arsenide, indium gallium phosphide and aluminum gallium arsenide or aluminum indium gallium phosphide are provided.

In one aspect, metal oxide compositions having electronic structure of multiple band gaps are described. In some embodiments, a metal oxide composition comprises a (Co,Ni)O alloy having electronic structure including multiple band gaps. The (Co,Ni)O alloy can include a first band gap and a second band gap, the first band gap separating valence and conduction bands of the electronic structure.

A light-receiving device of an embodiment of the present disclosure includes, on a first principal surface of a semiconductor layer, a pixel region that includes a plurality of light-receiving pixels each receiving light incident from side of a second principal surface of the semiconductor layer. The light-receiving device further includes, throughout a gap between the second principal surface and the pixel region, a low-impurity region having a relatively lower impurity concentration than the pixel region. The light-receiving pixels each include one or a plurality of photoelectric current extraction regions each including, on the first principal surface, an anode region and a cathode region, and a circuit region that is electrically coupled to each of the cathode regions and is electrically separated from the impurity region.

A light-receiving device of an embodiment of the present disclosure includes, on a first principal surface of a semiconductor layer, a pixel region that includes a plurality of light-receiving pixels each receiving light incident from side of a second principal surface of the semiconductor layer. The light-receiving device further includes, throughout a gap between the second principal surface and the pixel region, a low-impurity region having a relatively lower impurity concentration than the pixel region. The light-receiving pixels each include one or a plurality of photoelectric current extraction regions each including, on the first principal surface, an anode region and a cathode region, and a circuit region that is electrically coupled to each of the cathode regions and is electrically separated from the impurity region.

A solid-state image pickup device 1 according to the present invention includes a semiconductor substrate 2 on which a pixel 20 composed of a photodiode 3 and a transistor is formed. The transistor comprising the pixel 20 is formed on the surface of the semiconductor substrate, a pn junction portion formed between high concentration regions of the photodiode 3 is provided within the semiconductor substrate 2 and a part of the pn junction portion of the photodiode 3 is extended to a lower portion of the transistor formed on the surface of the semiconductor substrate 2. According to the present invention, there is provided a solid-state image pickup device in which a pixel size can be microminiaturized without lowering a saturated electric charge amount (Qs) and sensitivity.