International Business Machines Corporation

Egypt Nanotechnology Center

Ahmed Abou-Kandil

Devendra K Sadana

Jeehwan Kim

Keith E Fogel

Augustin J Hong

Mohamed Saad

Hisham S Mohamed

Osama Tobail

George Stojan Tulevski

Dennis Merton Newns

Glenn John Martyna

Ahmed Maarouf

Alessandro Curioni

Jee Hwan Kim

Wanda Andreoni

Mostafa M El-Ashry

Paul Michael Kozlowski

Petr Khomyakov

Nasser Afify

A Schottky-barrier-reducing layer is provided between a p-doped semiconductor layer and a transparent conductive material layer of a photovoltaic device. The Schottky-barrier-reducing layer can be a conductive material layer having a work function that is greater than the work function of the transparent conductive material layer. The conductive material layer can be a carbon-material layer such as a carbon nanotube layer or a graphene layer. Alternately, the conductive material layer can be another transparent conductive material layer having a greater work function than the transparent conductive material layer. The reduction of the Schottky barrier reduces the contact resistance across the transparent material layer and the p-doped semiconductor layer, thereby reducing the series resistance and increasing the efficiency of the photovoltaic device.

Photovoltaic devices with an interfacial band-gap modifying structure and methods for forming the same

A photovoltaic device includes a p-type layer. An intrinsic layer is formed directly on the p-type layer and includes an interface region extending into the intrinsic layer that includes a gradually decreasing band gap energy going from the p-type layer into the intrinsic layer formed by a graded deposition temperature. An n-type layer is formed directly on the intrinsic layer.

Temperature grading for band gap engineering of photovoltaic devices

A doped, passivated graphene nanomesh includes a graphene nanomesh, a plurality of nanoholes formed in a graphene sheet, and a plurality of carbon atoms which are formed adjacent to the plurality of nanoholes; a passivating element bonded to the plurality of carbon atoms; and a dopant bonded to the passivating element, the dopant comprising one of an electron-donating element for making the graphene nanomesh an n-doped graphene nanomesh, and an electron-accepting element for making the graphene nanomesh a p-doped graphene nanomesh.

Doped, passivated graphene nanomesh, method of making the doped, passivated graphene nanomesh, and semiconductor device including the doped, passivated graphene nanomesh

Methods for forming a photovoltaic device include adjusting a deposition power for depositing a buffer layer including germanium on a transparent electrode. The deposition power is configured to improve device efficiency. A p-type layer is formed on the buffer layer. An intrinsic layer and an n-type layer are formed over the p-type layer.

Enhancing efficiency in solar cells by adjusting deposition power

A method for fabricating a photovoltaic device includes depositing a p-type layer at a first temperature and depositing an intrinsic layer while gradually increasing a deposition temperature to a final temperature. The intrinsic layer deposition is completed at the final temperature. An n-type layer is formed on the intrinsic layer.

A method of producing a photovoltaic device includes providing a stretchable substrate for the photovoltaic device; and stretching the substrate to produce a stretched substrate. The method further includes depositing a structure comprising hydrogenated amorphous silicon onto the stretched substrate; and subjecting the deposited hydrogenated amorphous silicon structure and the stretched substrate to a compressive force to form a compressively strained photovoltaic device.

Silicon: hydrogen photovoltaic devices, such as solar cells, having reduced light induced degradation and method of making such devices

An electronic device includes a substrate and a plurality of particles anchored to the substrate. An electrode material is formed over the particles and configured to form peaks over the particles. One or more operational layers are fog led over the electrode material for performing a device function.

Photovoltaic device using nano-spheres for textured electrodes

A method of making a semiconductor device, includes providing a graphene sheet, creating a plurality of nanoholes in the graphene sheet to form a graphene nanomesh, the graphene nanomesh including a plurality of carbon atoms which are formed adjacent to the plurality of nanoholes, passivating a dangling bond on the plurality of carbon atoms by bonding a passivating element to the plurality of carbon atoms, and doping the passivated graphene nanomesh by bonding a dopant to the passivating element.

A p-doped semiconductor layer of a photovoltaic device is formed employing an inert gas within a carrier gas. The presence of the inert gas within the carrier gas increases free hole density within the p-doped semiconductor layer. This decreases the Schottky barrier at an interface with a transparent conductive material layer, thereby significantly reducing the series resistance of the photovoltaic device. The reduction of the series resistance increases the open-circuit voltage, the fill factor, and the efficiency of the photovoltaic device. This effect is more prominent if the p-doped semiconductor layer is also doped with carbon, and has a band gap greater than 1.85V. The p-doped semiconductor material of the p-doped semiconductor layer can be hydrogenated if the carrier gas includes a mix of Hand the inert gas.

Solar cell employing an enhanced free hole density p-doped material and methods for forming the same

Fabrication of a tandem photovoltaic device includes forming a bottom cell having an N-type layer, a P-type layer and a bottom intrinsic layer therebetween. A top cell is formed relative to the bottom cell. The top cell has an N-type layer, a P-type layer and a top intrinsic layer therebetween. The top intrinsic layer is formed of an undoped material deposited at a temperature that is different from the bottom intrinsic layer such that band gap energies for the top intrinsic layer and the bottom intrinsic layer are progressively lower for each cell.

Mixed temperature deposition of thin film silicon tandem cells

A hydrogenated thin film is formed in a controlled vacuum on a substrate by evaporating one or more solid materials and passing the resulting vapor and a hydrogen-containing gas into a space between two electrodes. One of the electrodes includes openings for allowing the vapor to enter the space. Plasma is generated within the space to cause dissociation of the hydrogen-containing gas and promote a reaction between the material(s) and hydrogen-containing gas.

Growing community of inventors

Elmsford, NY, United States of America

Ahmed Abou-Kandil