Thin-film semiconductor optoelectronic device with textured front and/or back surface prepared from etching
A method is provided for preparing at least one textured layer in an optoelectronic device. The method includes epitaxially growing a semiconductor layer of the optoelectronic device over a growth substrate; exposing the semiconductor layer to an etching process to create the at least one textured surface on the semiconductor layer; and lifting the optoelectronic device from the growth substrate.
1. A method for providing at least one textured layer in an optoelectronic device, the method comprising:
forming a reflective back metal layer having a flat surface;
forming an absorber layer on the reflective back metal layer to have a first thickness;
epitaxially growing a semiconductor layer to have a second thickness less than the first thickness of the absorber layer, with the semiconductor layer being positioned between the flat surface of the reflective back metal layer and the absorber layer; and
positioning an emitter layer between the absorber layer and the semiconductor layer, wherein the emitter layer and the absorber layer form a p-n junction of the optoelectronic device, wherein the absorber layer is further positioned between the semiconductor layer and a surface of the optoelectronic device on which light is to be incident.
2. The method of claim 1 , further comprising forming a planar interface between the emitter layer and the semiconductor layer.
3. The method of claim 1 , wherein the semiconductor layer includes at least one inhomogeneous textured surface.
4. The method of claim 1 , further comprising separating the optoelectronic device from a growth substrate via an epitaxial lift off (ELO) process.
5. The method of claim 3 , further comprising forming the at least one inhomogeneous textured surface to be configured to cause scattering of light.
6. The method of claim 5 , wherein the at least one inhomogeneous textured surface is configured to cause photons to scatter at randomized angles.
7. The method of claim 1 , wherein the semiconductor layer includes at least one or more of gallium, aluminum, indium, phosphorus, nitrogen, or arsenic.
8. The method of claim 1 , further comprising depositing, over the at least one textured layer, one or more of:
a dielectric layer,
a transparent conducting oxide (TCO) layer,
an anti-reflective coating, a metal reflective layer, or
a high-resistivity transparent (HRT) layer.
9. The method of claim 1 , forming at least one inhomogeneous textured surface to be part of a front window layer positioned closer to a front side of the optoelectronic device than the p-n junction of the optoelectronic device that includes the absorber layer.
10. The method of claim 1 , forming the optoelectronic device to be part of a solar cell or part of a light-emitting diode.