Optical absorption and charging effect in nano-crystalline Ge/SiNx multilayers

► Nanocrystalline Ge(nc-Ge)/SiNx multilayers with various size of nc-Ge are fabricated. ► The size-dependent optical absorption and band gap are observed. ► The carrier transport mechanism is dominated by space-charge limited current process. ► The charging storage effect is achieved in SiNx/nc-Ge/SiNx sandwiched structures.