Nonvolatile floating gate organic memory device based on pentacene/CdSe quantum dot heterojuction

An organic floating-gate memory device using CdSe quantum dots (QDs) as a charge-trapping element was fabricated. CdSe QDs were localized beneath a pentacene without any tunneling insulator, and the QD layer played a role as hole-trapping sites. The band bending formed at the junction between pentacene and QD layers inhibited back-injection of holes trapped in CdSe into pentacene, which appeared as a hysteretic capacitance-voltage response during the operation of the device. Nearly, 60 of trapped charge was sustained even after 10 ⁴s in programmed state, and this long retention time can be potentially useful in practical applications of non-volatile memory.