PHOTONIC DEVICE AND METHOD OF MAKING THE SAME

摘要

A photonic device (200) and method (100) of making the photonic device (200) employs preferential etching of grain boundaries of a polycrystalline semiconductor material layer (210). The method (100) includes growing (110) the polycrystalline layer (210) on a substrate (201). The polycrystalline layer includes a transition region (212) of variously oriented grains and a region (214) of columnar grain boundaries (215) adjacent to the transition region. The method further includes preferentially etching (120) the colunmar grain boundaries to provide tapered structures (220) of the semiconductor material that are continuous (217) with respective aligned grains (213) of the transition region. The tapered structures are predominantly single crystal. The method further includes forming (140) a conformal semiconductor junction (240) on the tapered structures and providing (160) first and second electrodes. The first electrode (201, 262) is adjacent to the transition region and the second electrode (260) is adjacent to a surface layer of the conformal semiconductor junction.