Embodiments of a photovoltaic device are provided herein. The photovoltaic device can include a layer stack and an absorber layer disposed on the layer stack. The absorber layer can include a first region and a second region. Each of the first region of the absorber layer and the second region of the absorber layer can include a compound comprising cadmium, selenium, and tellurium. An atomic concentration of selenium can vary across the absorber layer. The first region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. The second region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. A ratio of an average atomic concentration of selenium in the first region of the absorber layer to an average atomic concentration of selenium in the second region of the absorber layer can be greater than 10.

According to one embodiment, a photoelectric conversion element includes a photoelectric conversion layer, and a first member. The first member includes a first layer and a second layer. A direction from the second layer to the first layer is along a first direction from the photoelectric conversion layer to the first member. The first layer includes a plurality of particles and an intermediate region provided in at least a part of location between the plurality of particles. The plurality of particles include at least one selected from the group consisting of oxygen and sulfur and zinc. The intermediate region includes a rare earth element. The second layer includes a metal fluoride.

According to one embodiment, a photoelectric conversion element includes a photoelectric conversion layer, and a first member. The first member includes a first layer and a second layer. A direction from the second layer to the first layer is along a first direction from the photoelectric conversion layer to the first member. The first layer includes a plurality of particles and an intermediate region provided in at least a part of location between the plurality of particles. The plurality of particles include at least one selected from the group consisting of oxygen and sulfur and zinc. The intermediate region includes a rare earth element. The second layer includes a metal fluoride.

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.

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.

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.

An embodiment provides a semiconductor device package, the semiconductor device package comprising: a substrate including an electrode disposed on one surface; a metal sidewall disposed on the substrate while surrounding the electrode; a semiconductor device disposed on the electrode; and a light transmitting member disposed on the metal sidewall to cover the semiconductor device, wherein the metal sidewall has the inner surface and the outer surface which are corrugated, and includes: a first metal part disposed on the substrate; a second metal part disposed on the first metal part; and a third metal part disposed on the second metal part, and the inner surface or the outer surface of the metal sidewall includes a recess portion between the second metal part and the third metal part.

An embodiment provides a semiconductor device package, the semiconductor device package comprising: a substrate including an electrode disposed on one surface; a metal sidewall disposed on the substrate while surrounding the electrode; a semiconductor device disposed on the electrode; and a light transmitting member disposed on the metal sidewall to cover the semiconductor device, wherein the metal sidewall has the inner surface and the outer surface which are corrugated, and includes: a first metal part disposed on the substrate; a second metal part disposed on the first metal part; and a third metal part disposed on the second metal part, and the inner surface or the outer surface of the metal sidewall includes a recess portion between the second metal part and the third metal part.