Photoelectric properties of structures with GeSiSn|Ge multiple quantum wells and relaxed GeSiSn layers

The photoelectric properties of $p$-$i$-$n$ photodiodes including GeSiSn|Ge multiple quantum wells (MQWs) and relaxed GeSiSn layers on a Ge(1 0 0) substrate have been studied. Based on current-voltage characteristic measurements, it is shown that the lowest density of the dark current of $p$-$i$-$n$ photodiodes with a reverse bias of 1V reaches a value of 0.7 mA/cm$^2$. The cut-off wavelength for both diodes with MQWs and relaxed layers is about 2$\mu$m ($\sim$ 0.6 eV).