胶体CuFeS2纳米晶：中间Fe d带导致高光热转换效率
Colloidal CuFeS2 Nanocrystals: Intermediate Fe d-Band Leads to High Photothermal Conversion Efficiency
摘要：
我们描述了胶体热注射合成相纯纳米晶体（NC）的一个高度丰富的矿物，黄铜矿（CuFeS 2）。吸收带集中在480和950 nm左右，几乎跨越整个可见光和近红外区域，包括其光学消光特性。这些峰是由于电子从价带（VB）到空中间带（IB）的跃迁，位于基本带隙中，主要由Fe 3d轨道组成。激光照射（在808 nm）的CuFeS 2 NC的水悬浮液表现出显着的加热，光热转换效率为49%。这种有效的加热归因于宽IB带内的载流子弛豫（由于间接的VB-IB间隙），如瞬态吸收测量所证实的。这些NC在所谓的生物窗（650-900 nm）中的强吸收和高光热转换效率（PTE）使它们适合于光热治疗，如通过激光照射后的肿瘤细胞湮灭所证明的。通过对两种不同细胞系进行体外毒性试验，证实了这些NC在黑暗条件下的其他无害性质。构成IB的深Fe能级的存在是这种增强的PTE的起源，其可用于设计其他高性能NC光热剂。
英文摘要：
We describe the colloidal hot-injection synthesis of phase-pure nanocrystals (NCs) of a highly abundant mineral, chalcopyrite (CuFeS2). Absorption bands centered at around 480 and 950 nm, spanning almost the entire visible and near infrared regions, encompass their optical extinction characteristics. These peaks are ascribable to electronic transitions from the valence band (VB) to the empty intermediate band (IB), located in the fundamental gap and mainly composed of Fe 3d orbitals. Laser-irradiation (at 808 nm) of an aqueous suspension of CuFeS2 NCs exhibited significant heating, with a photothermal conversion efficiency of 49%. Such efficient heating is ascribable to the carrier relaxation within the broad IB band (owing to the indirect VB-IB gap), as corroborated by transient absorption measurements. The intense absorption and high photothermal transduction efficiency (PTE) of these NCs in the so-called biological window (650-900 nm) makes them suitable for photothermal therapy as demonstrated by tumor cell annihilation upon laser irradiation. The otherwise harmless nature of these NCs in dark conditions was confirmed by in vitro toxicity tests on two different cell lines. The presence of the deep Fe levels constituting the IB is the origin of such enhanced PTE, which can be used to design other high performing NC photothermal agents.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
