Thin-film semiconductor optoelectronic device with textured front and/or back surface prepared from etching
An optoelectronic device having a textured layer is described. In an aspect, a method may be used to produce the optoelectronic device, where the method includes epitaxially growing a semiconductor layer of the optoelectronic device on a growth substrate, and exposing the semiconductor layer to an etching process to create at least one textured surface in the semiconductor layer. The textured semiconductor layer can be referred to as a textured layer. The etching process is performed without the use of a template layer, or similar layer, configured as a mask to generate the texturing. The etching process can be done by one or more of a liquid or solution-based chemical etchant, gas etching, laser etching, plasma etching, or ion etching. The method can also include lifting the semiconductor layer of the optoelectronic device from the growth substrate by, for example, the use of an epitaxial lift off (ELO) process.
1. An optoelectronic device having at least one textured surface, comprising:
a reflective back metal layer having a flat surface;
an absorber layer formed on the reflective back metal layer and having a first thickness;
a semiconductor layer epitaxially grown, the semiconductor layer being a different layer than the absorber layer and having a second thickness less than the first thickness of the absorber layer, wherein the semiconductor layer is positioned between the flat surface of the reflective back metal layer and the absorber layer, wherein the semiconductor layer includes at least one inhomogeneous textured surface; and
an emitter layer positioned 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, and wherein an interface between the emitter layer and the semiconductor layer is planar,
wherein the absorber layer is positioned between the semiconductor layer and a surface of the optoelectronic device on which light is to be incident.
2. The optoelectronic device of claim 1 , wherein the optoelectronic device is separated from a growth substrate via an epitaxial lift off (ELO) process.
3. The optoelectronic device of claim 1 , wherein the at least one inhomogeneous textured surface is configured to cause scattering of light.
4. The optoelectronic device of claim 3 , wherein the at least one inhomogeneous textured surface is configured to cause photons to scatter at randomized angles.
5. The optoelectronic device of claim 1 , wherein the semiconductor layer includes at least one or more of gallium, aluminum, indium, phosphorus, nitrogen, or arsenic.
6. The optoelectronic device of claim 1 , further comprising depositing, over the at least one textured surface, 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.
7. The optoelectronic device of claim 1 , wherein the optoelectronic device is part of a solar cell or part of a light-emitting diode.