According to the embodiments provided herein, a photovoltaic device can include a buffer layer adjacent to an absorber layer doped p-type with a group V dopant. The buffer layer can have a plurality of layers compatible with group V dopants.

Provided is a stable CdZnTe monocrystalline substrate having a small leakage current even when a high voltage is applied and having a lower variation in resistivity with respect to variations in applied voltage values. A semiconductor wafer comprising a cadmium zinc telluride monocrystal having a zinc concentration of 4.0 at % or more and 6.5 at % or less and a chlorine concentration of 0.1 ppm by mass or more and 5.0 ppm by mass or less, wherein the semiconductor wafer has a resistivity of 1.0×10.sup.7 Ωcm or more and 1.0×10.sup.8 Ωcm or less when a voltage of 900 V is applied, and wherein a ratio (variation ratio) of the resistivity at application of 0 V to the resistivity at application of a voltage of 900 V is 20% or less.

According to the embodiments provided herein, a method for forming a photovoltaic device can include depositing a plurality of semiconductor layers. The plurality of semiconductor layers can include a doped layer that is doped with a group V dopant. The doped layer can include cadmium selenide or cadmium telluride. The method can include annealing the plurality of semiconductor layers to form an absorber layer.

A method for forming a hole transport layer on a surface of a substrate includes providing M target materials comprising inorganic hole transport materials and forming the hole transport layer on the surface of the substrate using magnetron sputtering. The hold transport layer at least comprises N consecutive sub-layers. M and N are integers and 2≤N≤M. One of the M target materials is a doped target material further comprising a doping material.

According to embodiments provided herein, the performance of photovoltaic device can be improved by rapidly heating an absorber layer of a device in open-circuit to a high temperature for a short period of time followed by rapid quenching. The rapid heating may be accomplished by one or more pulses of high intensity electromagnetic energy. The energy may be visible light. The energy may be absorbed primarily in the absorber layer, such that the absorber layer is preferentially heated, promoting chemical reactions of dopant complexes. The dopant chemical reactions disrupt compensating defect complexes that have formed in the device, and regenerate active carriers.

Provided are structures and methods for doping polycrystalline thin film semiconductor materials in photovoltaic devices. Embodiments include methods for forming and treating a photovoltaic semiconductor absorber layer.

A cadmium telluride solar cell and a preparation method thereof. The method includes providing a substrate, and forming a window layer on a first surface of the substrate, the window layer is made of magnesium-doped zinc oxide; forming a light absorbing layer on a surface of the window layer, the light absorbing layer includes a composite layer of cadmium selenide, selenium-doped cadmium telluride, and cadmium telluride; and forming a back electrode layer on a surface of the light absorbing layer. The use of the composite structure of cadmium selenide, selenium-doped cadmium telluride, and cadmium telluride allows the solar cell to absorb long-wavelength and short-wavelength light to the maximum, increases the short-circuit current density of the cell, and improves the efficiency of the cell. In addition, the window layer including magnesium-doped zinc oxide of the solar cell serves as a buffer layer to reduce the recombination of charge carriers between interfaces.

According to the embodiments provided herein, a method for forming a photovoltaic device can include depositing a plurality of semiconductor layers. The plurality of semiconductor layers can include a doped layer that is doped with a group V dopant. The doped layer can include cadmium selenide or cadmium telluride. The method can include annealing the plurality of semiconductor layers to form an absorber layer.

A doped photovoltaic device is presented. The photovoltaic device includes a semiconductor absorber layer or stack disposed between a front contact and a back contact. The absorber layer comprises cadmium, selenium, and tellurium doped with Ag, and optionally with Cu. The Ag dopant may be added to the absorber in amounts ranging from 5×10.sup.15/cm.sup.3 to 2.5×10.sup.17/cm.sup.3 via any of several methods of application before, during, or after deposition of the absorber layer. The photovoltaic device has improved Fill Factor and P.sub.MAX at higher P.sub.r(=I.sub.sc*V.sub.oc product) values, e.g. about 160 W, which results in improved conversion efficiency compared to a device not doped with Ag. Improved PT may result from increased I.sub.sc, increased V.sub.oc, or both.

Methods of forming a p-type IV-doped III-VI semiconductor are provided which comprise exposing a substrate to a vapor composition comprising a group III precursor comprising a group III element, a group VI precursor comprising a group VI element, and a group IV precursor comprising a group IV element, under conditions to form a p-type IV-doped III-VI semiconductor via metalorganic chemical vapor deposition (MOCVD) on the substrate. Embodiments make use of a flow ratio defined as a flow rate of the group VI precursor to a flow rate of the group III precursor wherein the flow ratio is below an inversion flow ratio value for the IV-doped III-VI semiconductor.