Abstract: A method is provided for fabricating a thin-film semiconductor substrate by forming a porous semiconductor layer conformally on a reusable semiconductor template and then forming a thin-film semiconductor substrate conformally on the porous semiconductor layer. An inner trench having a depth less than the thickness of the thin-film semiconductor substrate is formed on the thin-film semiconductor substrate. An outer trench providing access to the porous semiconductor layer is formed on the thin-film semiconductor substrate and is positioned between the inner trench and the edge of the thin-film semiconductor substrate. The thin-film semiconductor substrate is then released from the reusable semiconductor template.

Abstract: A three-dimensional solar cell comprising a semiconductor substrate with an inverted pyramidal cavity, emitter metallization regions on ridges on the surface of the semiconductor substrate which define an opening of the inverted pyramidal cavity, and base metallization regions on a region which form the apex of the inverted pyramidal cavity. A method for fabricating a three-dimensional thin-film solar cell from an inverted pyramidal three-dimensional thin-film silicon substrate by doping ridges on the surface of the semiconductor substrate which define an opening of an inverted pyramidal cavity on the substrate to form an emitter region, and doping a region which forms the apex of the inverted pyramidal cavity to form a base region. Adding a surface passivation layer to the surface of the substrate. Selectively etching the passivation layer from the emitter region and base region. Then concurrently metallizing the emitter region and base region.

Abstract: The present disclosure relates to methods and apparatuses for fracturing or breaking a buried porous semiconductor layer to separate a 3-D thin-film semiconductor semiconductor (TFSS) substrate from a 3-D crystalline semiconductor template. The method involves forming a sacrificial porous semiconductor layer on the 3-D features of the template. A variety of techniques may be used to fracture and release the mechanically weak porous semiconductor layer without damaging the TFSS substrate layer or the template layer such as pressure variations, thermal stress generation, and mechanical bending. The methods also allow for processing three dimensional features not possible with current separation processes. Optional cleaning and final lift-off steps may be performed as part of the release step or after the release step.

Abstract: A semiconductor template having a top surface aligned along a (100) crystallographic orientation plane and an inverted pyramidal cavity defined by a plurality of walls aligned along a (111) crystallographic orientation plane. A method for manufacturing a semiconductor template by selectively removing silicon material from a silicon template to form a top surface aligned along a (100) crystallographic plane of the silicon template and a plurality of walls defining an inverted pyramidal cavity each aligned along a (111) crystallographic plane of the silicon template.

Abstract: A three-dimensional thin-film semiconductor substrate having a plurality of ridges on the surface of the semiconductor substrate which define a base opening of an inverted pyramidal cavity and walls defining the inverted pyramidal cavity is provided. And a fabrication method for a 3-D TFSS by forming a porous silicon layer on a silicon template having a top surface aligned along a (100) crystallographic orientation plane of the silicon template and a plurality of walls each aligned along a (111) crystallographic orientation plane of the silicon template and forming an inverted pyramidal cavity. The porous silicon layer forms substantially conformal on the silicon template. Then forming a substantially conformal epitaxial silicon layer on the porous silicon layer and releasing the epitaxial silicon layer from the silicon template.

Abstract: The present disclosure presents a partially-transparent (see-through) three-dimensional thin film solar cell (3-D TFSC) substrate. The substrate includes a plurality of unit cells. Each unit cell structure has the shape of a truncated pyramid, and its parameters may be varied to allow a desired portion of sunlight to pass through.

Abstract: Methods here disclosed provide for selectively coating the top surfaces or ridges of a 3-D substrate while avoiding liquid coating material wicking into micro cavities on 3-D substrates. The substrate includes holes formed in a three-dimensional substrate by forming a sacrificial layer on a template. The template includes a template substrate with posts and trenches between the posts. The steps include subsequently depositing a semiconductor layer and selectively etching the sacrificial layer. Then, the steps include releasing the semiconductor layer from the template and coating the 3-D substrate using a liquid transfer coating step for applying a liquid coating material to a surface of the 3-D substrate. The method may further include coating the 3-D substrate by selectively coating the top ridges or surfaces of the substrate.