Flexible Ge-on-polyimide detectors

A flexible Ge-on-polyimide photodetector is demonstrated. The single crystalline thin film of Ge was transferred on the polyimide by adhesive wafer bonding and smart-cut techniques. A simple tunneling metal-oxide-semiconductor structure is fabricated for the detector applications. Due to the transparency of the polyimide, the responsivity of the detector is sensitive to the environments. At −2 V, the photodetector on the stainless steel has responsivities of 220, 200, and 140 mA/W at wavelength of 850, 1310, and 1550 nm, respectively.