PV Device with Graded Grain Size and S:Se Ratio

摘要

Disclosed herein are CIGS-based photon-absorbing layers disposed on a substrate. The photon-absorbing layers are useful in photovoltaic devices. The photon absorbing-layer is made of a semiconductor material having empirical formula AB1-xB′xC2-yC′y, where A is Cu, Zn, Ag or Cd; B and B′ are independently Al, In or Ga; C and C′ are independently S, or Se, and wherein 0≦x≦1; and 0≦y≦2. The grain size of the semiconductor material and the composition of the semiconductor material both vary as a function of depth across the layer. The layers described herein exhibit improved photovoltaic properties, including increased shunt resistance and decreased backside charge carrier recombination.

主权项

1. A photovoltaic device component, comprising:
a substrate, and a photon-absorbing layer disposed on the substrate and having a surface near the substrate and a surface distant from the substrate the photon-absorbing layer comprising grains of semiconductor material having empirical formula AB1-xB′xC2-yC′y, where A is Cu, Zn, Ag or Cd; B and B′ are independently Al, In or Ga; C and C′ are independently S, or Se, and wherein 0≦x≦1; and 0≦y≦2, wherein the photon-absorbing layer comprises at least one sulphur-rich region and at least one sulphur poor region and wherein the grains of semiconductor material near the surface distant from the substrate are larger than the grains near the surface near the substrate.