Ultra-fast switching in solution processed quantum dot based non-volatile resistive memory

Abstract

In this letter, we report a facile quantum dot based non-volatile resistive memory device with a switching speed of 10 ns and ON/OFF ratio of 10 000. The device showed excellent endurance characteristics for 100 000 switching cycles. Retention tests showed good stability and the devices are reproducible. Memory operating mechanism is proposed based on charge trapping in quantum dots with AlOx acting as barrier. This mechanism is supported by marked variation in capacitance value in ON and OFF states.

Controllable switching ratio in quantum dot/metal–metal oxide nanostructure based non-volatile memory device

“…Energy dispersive spectra (EDS) of the same layer showed presence of indium and excess oxygen, suggesting the presence of indium oxide. Our previous works with similar device structures but with different metals like aluminum and titanium yielded in analogous results [11][12][13]. The operating mechanism of such devices were described on the basis of charge trapping in a well-barrier structure where CdSe quantum dots act as trap centers and metal-oxide constitutes the barrier.…”

“…The memory device based on such structure can be expected to be much faster due to less tunneling time [7,10]. Quantum dots embedded in a partially oxidized thin aluminum/titanium layer exhibited bipolar bistable non-volatile memory characteristics with excellent ON/OFF ratio and ultrafast switching times (10 ns) [11][12][13]. In this report, we present the memory characteristics of the device with structure ITO/CdSe QD/InInOx/CdSe QD/In and present a comparative analysis of performance of the memory devices with different metals.…”

Possible application of lead sulfide quantum dot in memory device

“…Resistive switching is classified as bipolar switching and unipolar switching [10,11]. Bipolar and unipolar resistive switching mechanisms with bi-stability has been reported in CdSe QD devices, ZnO-single-wire memristor, and Au QDs in polymide (PI) layer with R OFF /R ON from 10 2 to 10 8 [12][13][14].…”

“…Motivated by the fact that memory effect in nonvolatile memory based on hybrid nanocomposites is strongly correlated with the presence of inorganic nanomaterials (ZnO QDs, Au NPs, CdSe NPs, and carbon nanotubes) embedded in a polymer matrix [12][13][14][15][16][17], an investigation was carried out to study R OFF /R ON ratio, retentivity, and conduction mechanism in the as-fabricated Al/polyvinyl alcohol (PVA)/lead sulfide QD (PbS QD)/ITO device for possible application as memory device. This paper reports on the observed R OFF /R ON ratio of 3.15 × 10 3 with retentivity for prolonged time.…”

CdSe quantum dot/AlOx based non-volatile resistive memory

“…While the physical limit of the write time for quantum dots is in the picoseconds range. Quantum dots embedded in a partially oxidized thin aluminum/titanium layer exhibited bipolar bistable non-volatile memory characteristics with excellent ON/OFF ratio and fast switching times [19][20][21]. In this paper, we present a bipolar non-volatile resistive memory device, exclusively based on spin casted quantum dot/metal/quantum dot structure with ON/OFF ratio [10,000 with CdSe quantum dot size *5.2 nm.…”