Abstract: A photodiode device and the manufacturing method of the same are provided. The photodiode device includes a substrate; an epitaxy layer on the substrate, the epitaxy layer including a window layer and a cap layer on the window layer, the cap layer covering a portion of the window layer; and a patterned conductive layer on the cap layer, the patterned conductive layer being formed with a bottom area and a top area wherein the bottom area is greater than the top area.

Abstract: A multi-junction solar cell structure includes a supporting substrate, a Group IV element-based thin film, and a Group III-V element-based thin film sequentially stacked on the supporting substrate. When the multi-junction solar cell structure is active, the Group III-V element-based thin film contacts the light before the Group IV element-based thin film does. The Group IV element-based thin film includes a first solar cell and the Group III-V element-based thin film includes a second solar cell, wherein the band gap of the first solar cell is lower than the band gap of the second solar cell.

Abstract: A method of manufacturing photodiode device includes the following steps: providing a wafer having a substrate and an epitaxy layer, the substrate having a first surface and a second surface and the epitaxy layer formed on the first surface; forming a first conductive layer on the second surface of the substrate; forming a patterned conductive layer above the epitaxy layer; and etching the patterned conductive layer by a reactive ion etching (RIE) process performed under argon gas and helium gas.