An imaging module (114) of an imaging system comprises a porous silicon membrane (116) with a first side (208), a contact side (210) opposite the first side, columns of silicon (212) configured to extend from the first side to the contact side, and columnar holes (214, 502) interlaced with the columns of silicon and configured to extend from the first side to the contact side. The imaging module further includes quantum dots (118) in the columnar holes. The imaging module further includes a metal pad (120) electrically coupled to the columns of silicon of the porous silicon membrane. The quantum dots in the columnar holes are electrically insulated from the metal pad. The imaging module further includes a substrate (122) with an electrically conductive pad (204) in electrical communication with the metal pad that defines a pixel.

A photovoltaic (PV) device with improved blue response. The PV device includes a silicon substrate with an emitter layer on a light receiving side. The emitter layer has a low dopant level such that it has sheet resistance of 90 to 170 ohm/sq. Anti-reflection in the PV device is provided solely by a nano-structured or black silicon surface on the light-receiving surface, through which the emitter is fanned by diffusion. The nanostructures of the black silicon are formed in a manner that does not result in gold or another high-recombina-tion metal being left in the black silicon such as with metal-assisted etching using silver. The black silicon is further processed to widen these pores so as to provide larger nanostruc-tures with lateral dimensions in the range of 65 to 150 nanometers so as to reduce surface area and also to etch away a highly doped portion of the emitter.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.

An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

Perovskite/silicon tandem solar cells have the potential to achieve high efficiencies through improvements to the optical and electrical parameters of perovskite/silicon tandem devices, via photon management, particularly using the optical band-edge shifting properties of silicon via surface modification of silicon. Silicon can directly extract the light generated charge carriers, which can achieve an efficiency of over 28%.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

In one aspect, nanostructured films are described herein comprising controlled architectures on multiple length scales (e.g. ≥3). As described further herein, the ability to control film properties on multiple length scales enables tailoring structures of the films to specific applications including, but not limited to, optoelectronic, catalytic and photoelectrochemical cell applications. In some embodiments, a nanostructured film comprises a porous inorganic scaffold comprising particles of an electrically insulating inorganic oxide. An electrically conductive metal oxide coating is adhered to the porous inorganic scaffold, wherein the conductive metal oxide coating binds adjacent particles of the insulating inorganic oxide.