Disorders and oxygen vacancies in p‐type Sn2B2O7 (B=Nb, Ta): Role of the B‐site element
Disorders and oxygen vacancies in p‐type Sn2B2O7 (B=Nb, Ta): Role of the B‐site element
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p 型 Sn2B2O7 (B=Nb, Ta) 中的无序和氧空位：B 位元素的作用
DOI：
10.1111/jace.18830
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发表时间：
2022
影响因子：
3.9
通讯作者：
Nishio Keishi
中科院分区：
文献类型：
--
作者：
Samizo Akane;Minohara Makoto;Kikuchi Naoto;Ando Kenta;Mazuka Yuta;Nishio Keishi
具有烧绿石结构的Sn 2Nb 2 − xTaxO 7（x= 0.0-2.0）是一种很有前途的p型氧化物半导体材料。系统研究了其Nb/Ta比，发现Nb端（Sn_2Nb_2O_7）的空穴产生效率比Ta端（Sn_2Ta_2O_7）低一个数量级。虽然这是由于氧空位形成的差异而发生的，但由于烧绿石Sn 2Nb 2 O 7和Sn 2 Ta 2 O 7中局部和全局晶体结构紊乱的信息有限，空穴产生效率的起源仍然不清楚。在这项研究中，Sn 2B 2 O 7（B = Nb，Ta），由BO 6八面体和Sn 4 O四面体组成的晶体结构，使用X射线吸收光谱和X射线衍射进行了研究。的本地和全球的晶体结构的详细调查表明，在Sn 2Nb 2 O 7的Sn 4 O四面体相比，Sn 2 Ta 2 O 7的无序更大的量;在BO 6八面体的无序只发生在Sn 2 Ta 2 O 7。本研究表明，适当选择B位元素对于抑制Sn 4 O四面体中的缺陷和无序形成以及随后提高空穴载流子产生效率至关重要。
Sn2Nb2−xTaxO7(x= 0.0–2.0) with pyrochlore structure is a promising material for p‐type oxide semiconductors. A systematic study of its Nb/Ta ratio indicated that the hole–generation efficiency of the Nb end (Sn2Nb2O7) was an order of magnitude lower than that of the Ta end (Sn2Ta2O7). Although this occurs due to differences in oxygen‐vacancy formation, the origins of the hole–generation efficiencies remain unclear due to limited information on local and global crystal‐structure disorders in pyrochlore Sn2Nb2O7and Sn2Ta2O7. In this study, the crystal structures of Sn2B2O7(B = Nb, Ta), composed of BO6octahedra and Sn4O tetrahedra, were investigated using X‐ray absorption spectroscopy and X‐ray diffraction. A detailed investigation of the local and global crystal structures indicated a larger amount of disorder in the Sn4O tetrahedra in Sn2Nb2O7compared to Sn2Ta2O7; disorder in the BO6octahedra occurred only in Sn2Ta2O7. This study indicates that an appropriate selection of the B‐site element is vital for suppressing defect and disorder formation in Sn4O tetrahedra and subsequently improving the hole–carrier–generation efficiency.