我們可以利用常見的矽金氧半結構來偵測光子能量大於1.1 eV 的光，受限於矽的能帶間隙，在1.3 mm 和1.55 mm 的紅外光則無法被偵測到。藉由鍺材料的引入，1.3 mm 和1.55 mm的紅外光就能順利的被偵測到。薄膜鍺能藉由晶圓接合與聰明切的方式來轉移到絕緣層、玻璃基板與聚亞醯胺基座上。使用薄膜鍺，可有效的降低成本，而不同的基座則可以運用在不同的功能上。利用矽鍺量子點與極薄的硼摻雜，量子點紅外光偵測器能達到寬帶的頻譜。矽與矽鍺異質接面會在價帶不連續產生量子點。硼摻雜除了可以提供電洞至量子點中，其本身亦形成一量子井。在紅外光的照射下，矽鍺量子點與硼摻雜量子井中侷限的電洞就能被激發而形成光電流。

Using Si metal-oxide-semiconductor structure, the light with photon energy larger than 1.1 eV can be detected at inversion bias. Due to Si bandgap, the near infrared at 1.3 mm and 1.55 mm can not be detected. With Ge incorporation, 1.3 mm and 1.55 mm infrared can be detected. Thin film Ge can be transferred on insulator, glass, and polyimide for different applications by wafer bonding and smartcut, and the cost can be reduced. The broadband absorption of SiGe/Si quantum dot infrared photodetectors are demonstrated using boron d doping in the Si spacer. The large valence band offset between Si and SiGe forms discrete quantum states in SiGe QDs. The d doping in Si spacers provides the QDs with a sufficient hole concentration and forms a d-doping well in Si. Under infrared exposure, the confined holes in QDs and d-doping wells can be excited and contribute to the photocurrent.