A photovoltaic device includes a substrate, a semiconductor stack and a transparent tunnel junction. The semiconductor stack includes an n-type layer selected from a first transparent conductive oxide layer, or a window layer, or both; and a p-type absorber layer disposed on the n-type layer, wherein the absorber layer consists essentially of CdSe.sub.xTe.sub.(1-x), wherein x is from 1 to about 40 at. %. The transparent tunnel junction comprises a transparent interface layer of Cd.sub.yZn.sub.(1-y)Te doped to be p+type, and a transparent contact layer doped to be n+type, and the interface layer is disposed between the p-type absorber layer and the transparent contact layer. In bifacial embodiments, the tunnel junction forms a transparent back contact and electrode; and in multi-junction embodiments, the tunnel junction forms a diode-like connector between top and bottom cells. The transparent contact layer may comprise tin oxide or zinc oxide doped with aluminum, fluorine or indium.

Photovoltaic devices with type II-VI semiconductor absorber materials having improved carrier extraction layers are described herein. Methods of treating semiconductor absorber layers and forming improved carrier extraction layers and p-type contact layers are described.

Photovoltaic devices with type II-VI semiconductor absorber materials having improved carrier extraction layers are described herein. Methods of treating semiconductor absorber layers and forming improved carrier extraction layers and p-type contact layers are described.

The present application discloses a zinc oxide-crystalline silicon laminated solar cell and a preparation method thereof, relates to the technical field of solar cells, and aims to solve the technical problem of low photoelectric conversion rate of existing solar cells. The zinc oxide-crystalline silicon laminated solar cell includes: a P-type silicon substrate layer; a front surface of the P-type silicon substrate layer being sequentially formed with, from bottom to top, a diffusion layer, an N-type zinc oxide layer, a first passivation layer, and a first antireflection layer; wherein the N-type zinc oxide layer is made of tetrapod-like N-type zinc oxide whisker powder as a raw material; and a back surface of the P-type silicon substrate layer being sequentially formed with, from top to bottom, a second passivation layer and a second antireflection layer; and an electrode, the electrode including a front electrode and a back electrode.

The present application discloses a zinc oxide-crystalline silicon laminated solar cell and a preparation method thereof, relates to the technical field of solar cells, and aims to solve the technical problem of low photoelectric conversion rate of existing solar cells. The zinc oxide-crystalline silicon laminated solar cell includes: a P-type silicon substrate layer; a front surface of the P-type silicon substrate layer being sequentially formed with, from bottom to top, a diffusion layer, an N-type zinc oxide layer, a first passivation layer, and a first antireflection layer; wherein the N-type zinc oxide layer is made of tetrapod-like N-type zinc oxide whisker powder as a raw material; and a back surface of the P-type silicon substrate layer being sequentially formed with, from top to bottom, a second passivation layer and a second antireflection layer; and an electrode, the electrode including a front electrode and a back electrode.

According to the embodiments provided herein, a photovoltaic device can include an absorber layer. The absorber layer can be doped p-type with a Group V dopant and can have a carrier concentration of the Group V dopant greater than 410.sup.15 cm.sup.3. The absorber layer can include oxygen in a central region of the absorber layer. The absorber layer can include an alkali metal in the central region of the absorber layer. Methods for carrier activation can include exposing an absorber layer to an annealing compound in a reducing environment. The annealing compound can include cadmium chloride and an alkali metal chloride.

According to the embodiments provided herein, a photovoltaic device can include an absorber layer. The absorber layer can be doped p-type with a Group V dopant and can have a carrier concentration of the Group V dopant greater than 410.sup.15 cm.sup.3. The absorber layer can include oxygen in a central region of the absorber layer. The absorber layer can include an alkali metal in the central region of the absorber layer. Methods for carrier activation can include exposing an absorber layer to an annealing compound in a reducing environment. The annealing compound can include cadmium chloride and an alkali metal chloride.

A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer comprises selenium, wherein an atomic concentration of selenium varies across a thickness of the absorber layer. The photovoltaic device is substantially free of a cadmium sulfide layer.

A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer comprises selenium, wherein an atomic concentration of selenium varies across a thickness of the absorber layer. The photovoltaic device is substantially free of a cadmium sulfide layer.

Provided are a solar cell and a light emitting device with low leakage current and low cost, using ZnO fine particles. A p-type ZnO layer (p-type layer) made primarily of p-type ZnO fine particles is formed. P-side electrodes are formed at a plurality of regions on the p-type layer. A thin insulating layer is formed between an n-type layer and the p-type layer. In the insulating layer, openings are formed at regions A each not overlapping the p-side electrodes and being apart from them in a plan view. In the configuration, by thus making the p-side electrodes apart from the regions A, the length of a current path in the p-type layer can be made substantially larger than the layer thickness.