Patent ID: 8389388

Claim:
A method ( 100 ) of making a photonic device ( 200 ) comprising: growing ( 110 ) a polycrystalline layer ( 210 ) of a semiconductor material on a substrate ( 201 ), the polycrystalline layer ( 210 ) comprising a transition region ( 212 ) of variously oriented small grains adjacent to the substrate ( 201 ) and a region ( 214 ) of relatively larger grains delineated by columnar grain boundaries ( 215 ) adjacent to the transition region ( 212 ); preferentially etching ( 120 ) the columnar grain boundaries ( 215 ) to the transition region ( 212 ) to provide tapered structures ( 220 ) of the semiconductor material that are continuous ( 217 ) with respective aligned grains ( 213 ) of the transition region ( 212 ), the tapered structures ( 212 ) being predominantly single crystal; forming ( 140 ) a conformal semiconductor junction ( 240 ) on the tapered structures ( 220 ); and providing ( 160 ) a first electrode ( 201 , 262 ) adjacent to the transition region ( 212 ) and a second electrode ( 260 ) adjacent to a surface layer of the conformal semiconductor junction ( 240 ).