Due to strong Coulomb interactions, reduced screening effects, and quantum confinement, transition-metal dichalcogenide (TMD) monolayer quantum disks (MQDs) are expected to exhibit large exciton binding energy, which is beneficial for the investigation of many-body physics at room temperature. Here, we report the first observations of room-temperature many-body effects in tungsten disulfide (WS₂) MQDs by both optical measurements and theoretical studies. The band-gap renormalization in WS₂ MQDs was about 250 ± 15 meV as the carrier density was increased from 0.6(±0.2) × 10¹² to 8.3(±0.2) × 10¹² cm⁻². We observed a striking exciton binding energy as large as 990 ± 30 meV at the lowest carrier density, which is larger than that in WS₂ monolayers. The huge exciton binding energy in WS₂ MQDs is attributed to the extra quantum confinement in the lateral dimension. The band-gap renormalization and exciton binding energies are explained using efficient reduced screening. On the basis of the Debye screening formula, the Mott density in WS₂ MQDs was estimated to be ~3.95 × 10¹³ cm⁻². Understanding and manipulation of the many-body effects in two-dimensional materials may open up new possibilities for developing exciton-based optoelectronic devices.

由于强大的库仑相互作用，降低的屏蔽作用和量子限制，过渡金属二硫化碳（TMD）单层量子盘（MQD）有望表现出大的激子结合能，这对于室温下多体物理学的研究是有益的。在这里，我们通过光学测量和理论研究报告了对二硫化钨（WS ₂）MQD中室温多体效应的首次观察。随着载流子密度从0.6（±0.2）×10 ¹²增加到8.3（±0.2）×10 ¹²  cm ^-2，WS ₂ MQD中的带隙重归一化约为250±15 meV。我们在最低载流子密度下观察到了惊人的激子结合能，最大为990±30 meV，这比WS ₂单层的更大。WS ₂ MQD中巨大的激子结合能归因于横向尺寸上的额外量子限制。带隙重归一化和激子结合能用有效减少的筛选来解释。根据德拜筛选公式，估计WS ₂ MQD中的Mott密度为〜3.95×10 ¹³  cm ^-2。理解和操纵二维材料中的多体效应可能为开发基于激子的光电器件开辟新的可能性。