Sr(Ag 1−x Li x ) 2 Se 2 and [Sr 3 Se 2 ][(Ag 1−x Li x ) 2 Se 2 ] Tunable Direct Band Gap Semiconductors
Sr(Ag 1−x Li x ) 2 Se 2 and [Sr 3 Se 2 ][(Ag 1−x Li x ) 2 Se 2 ] Tunable Direct Band Gap Semiconductors
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Sr(Ag 1–x Li x ) 2 Se 2 和 [Sr 3 Se 2 ][(Ag 1–x Li x ) 2 Se 2 ] 可调谐直接带隙半导体
DOI：
10.1002/anie.202301191
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Kanatzidis, Mercouri G.
中科院分区：
文献类型：
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作者：
Zhou, Xiuquan;Wilfong, Brandon;Chen, Xinglong;Laing, Craig;Pandey, Indra R.;Chen, Ying‐Pin;Chen, Yu‐Sheng;Chung, Duck‐Young;Kanatzidis, Mercouri G.
在熔融焊剂中合成固体，可使可溶性物质在低于固态反应的温度下快速扩散，从而形成动力学稳定的化合物晶体。在这项研究中，我们证明了混合氢氧化物和卤化物熔剂在合成复杂的Sr/Ag/Se在混合LiOH/LiCl的有效性。我们已经获得了一系列二维Sr（Ag 1 −xLix）2Se 2层状相。随着LiOH/LiCl比例的增加或反应温度的升高，Li部分取代Ag形成Sr（Ag 1-xLix）2Se 2的固溶体，x最高可达0.45。此外，通过Sr（Ag 1-xLix）2Se 2与SrSe的进一步反应，合成了一种新型的共生化合物[Sr 3Se 2][（Ag 1-xLix）2Se 2]。Sr（Ag 1 −xLix）2Se 2和[Sr 3Se 2][（Ag 1 −xLix）2Se 2]都表现出直接带隙，其随着Li取代度（x）的增加而增加。因此，Sr（Ag 1-xLix）2Se 2的带隙可以通过仅由通量比和温度控制的微调x来精确地调节。
Synthesizing solids in molten fluxes enables the rapid diffusion of soluble species at temperatures lower than in solid‐state reactions, leading to crystal formation of kinetically stable compounds. In this study, we demonstrate the effectiveness of mixed hydroxide and halide fluxes in synthesizing complex Sr/Ag/Se in mixed LiOH/LiCl. We have accessed a series of two‐dimensional Sr(Ag1−xLix)2Se2layered phases. With increased LiOH/LiCl ratio or reaction temperature, Li partially substituted Ag to form solid solutions of Sr(Ag1−xLix)2Se2withxup to 0.45. In addition, a new type of intergrowth compound [Sr3Se2][(Ag1−xLix)2Se2] was synthesized upon further reaction of Sr(Ag1−xLix)2Se2with SrSe. Both Sr(Ag1−xLix)2Se2and [Sr3Se2][(Ag1−xLix)2Se2] exhibit a direct band gap, which increases with increasing Li substitution (x). Therefore, the band gap of Sr(Ag1−xLix)2Se2can be precisely tuned via fine‐tuningxthat is controlled by only the flux ratio and temperature.