Botella Pablo, Enrichi Francesco, Vomiero Alberto, Muñoz-Santiuste Juan E, Garg Alka B, Arvind Ananthanarayanan, Manjón Francisco J, Segura Alfredo, Errandonea Daniel
Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, Sweden.
Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, via Torino 155, 30172 Venezia, Italy.
ACS Omega. 2020 Jan 30;5(5):2148-2158. doi: 10.1021/acsomega.9b02862. eCollection 2020 Feb 11.
We explore the potential of Tb- and Yb-doped InVO, InTaO, and InNbO for applications as phosphors for light-emitting sources. Doping below 0.2% barely change the crystal structure and Raman spectrum but provide optical excitation and emission properties in the visible and near-infrared (NIR) spectral regions. From optical measurements, the energy of the first/second direct band gaps was determined to be 3.7/4.1 eV in InVO, 4.7/5.3 in InNbO, and 5.6/6.1 eV in InTaO. In the last two cases, these band gaps are larger than the fundamental band gap (being indirect gap materials), while for InVO, a direct band gap semiconductor, the fundamental band gap is at 3.7 eV. As a consequence, this material shows a strong self-activated photoluminescence centered at 2.2 eV. The other two materials have a weak self-activated signal at 2.2 and 2.9 eV. We provide an explanation for the origin of these signals taking into account the analysis of the polyhedral coordination around the pentavalent cations (V, Nb, and Ta). Finally, the characteristic green (D → F ) and NIR (F → F) emissions of Tb and Yb have been analyzed and explained.
我们探究了掺铽（Tb）和镱（Yb）的钒酸铟（InVO）、钽酸铟（InTaO）和铌酸铟（InNbO）作为发光源磷光体的应用潜力。低于0.2%的掺杂几乎不会改变晶体结构和拉曼光谱，但能在可见光和近红外（NIR）光谱区域提供光激发和发射特性。通过光学测量，确定了InVO中第一/第二直接带隙的能量为3.7/4.1电子伏特（eV），InNbO中为4.7/5.3 eV，InTaO中为5.6/6.1 eV。在后两种情况下，这些带隙大于基本带隙（为间接带隙材料），而对于直接带隙半导体InVO，其基本带隙为3.7 eV。因此，这种材料显示出以2.2 eV为中心的强自激活光致发光。另外两种材料在2.2 eV和2.9 eV处有较弱的自激活信号。我们结合对五价阳离子（V、Nb和Ta）周围多面体配位的分析，对这些信号的起源进行了解释。最后，对Tb和Yb的特征绿色（D→F ）和近红外（F→F）发射进行了分析和解释。
