We report on the principle and realization of a new trap for excitons--the diamond electrostatic trap--which uses a single electrode to create a confining potential for excitons. We also create elevated diamond traps which permit evaporative cooling of the exciton gas. We observe the collection of excitons towards the trap center with increasing exciton density. This effect is due to screening of disorder in the trap by the excitons. As a result, the diamond trap behaves as a smooth parabolic potential which realizes a cold and dense exciton gas at the trap center.
Single-layer MoS
2
has been reported to exhibit strong
excitonic and trionic signatures in its photoluminescence (PL) spectra.
Here, we report that the emission spectra of MoS
2
QDs strongly
depend on the dielectric constant of the solvent and the relative
difference in the electronegativity between the solvent and QDs. Due
to the difference in electronegativity, electrons are either added
to the QD or withdrawn from it. Consequently, depending upon the dielectric
permittivity and the electronegativity of the surrounding medium,
the signature peaks of excitons and trions exhibit a significant change
in the PL spectra of MoS
2
QDs. Our findings are helpful
to understand the effect of the surrounding environment on the optical
properties of QDs and the importance of the selection of solvent since
MoS
2
QDs are potential candidates for valleytronics applications.
Brain-inspired computation that mimics the coordinated functioning of neural networks through multitudes of synaptic connections is deemed to be the future of computation to overcome the classical von Neumann bottleneck. The future artificial intelligence circuits require scalable electronic synapse (e-synapses) with very high bit densities and operational speeds. in this respect, nanostructures of two-dimensional materials serve the purpose and offer the scalability of the devices in lateral and vertical dimensions. in this work, we report the nonvolatile bipolar resistive switching and neuromorphic behavior of molybdenum disulfide (MoS 2) quantum dots (QD) synthesized using liquid-phase exfoliation method. The ReRAM devices exhibit good resistive switching with an On-Off ratio of 10 4 , with excellent endurance and data retention at a smaller read voltage as compared to the existing MoS 2 based memory devices. Besides, we have demonstrated the e-synapse based on MoS 2 QD. Similar to our biological synapse, paired pulse facilitation / Depression of short-term memory has been observed in these MoS 2 QD based e-synapse devices. this work suggests that MoS 2 QD has potential applications in ultra-high-density storage as well as artificial intelligence circuitry in a costeffective way.
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