La-doped PbZrTiO3(PLZT) thin film optical detectors (TOD) for retinal implantation-a "bionic" eye

A new ceramic optical microdetector has been developed for retinal implant as a direct replacement for damaged retinal photo-detectors in patients with dystrophies such as Retinitis Pigmentosa (RP) and Age-related Macular degeneration (AMD). The thin film optical detector (TOD) is a heterostructure device composed of an atomically ordered La-doped PbZrTiO₃(PLZT) layer epitaxially grown on an atomically ordered Pt thin film layer. The TOD has an optical response, which in the visible region has a peak at around 550 nm with a sensitivity that overlaps the eye response from 400 nm to 650 nm. The device responsivity in the visible range is at a value of ∼ 1000 V/W. Individual detectors are fabricated by photolithography and etch processing as is common in the microelectronics industry. Detectors 40 μm in diameter have been processed and have been integrated with a newly developed polymer carrier layer technique for ease of handling and implantation of microdetector arrays into the eye.