Grupo de Engenharia e Espectroscopia de Materiais, Departamento de Física, Universidade Federal de Juiz de Fora, Juiz de Fora, MG 36036-900 Brazil.
Laboratório de Novos Materiais Nanoestruturados e Funcionais, Instituto de Física, Universidade Federal de Alagoas, Maceió, AL 57072-900 Brazil.
Sci Rep. 2023 May 10;13(1):7627. doi: 10.1038/s41598-023-34591-0.
Doping glass with semiconductors, particularly with nanostructured semiconductors, has attracted attention due to the large optical absorption cross-sections of the latter. Based on this property, Ni[Formula: see text] (5 wt%) doped phosphate glass and Zn[Formula: see text]Ni[Formula: see text]Te (x = 0.5, 1.0, 5.0 and 10.0 wt% of Ni[Formula: see text]) nanocrystals (NCs) doped phosphate glasses (GCs) were prepared by fusion method and subsequent heat treatment. Influence of Ni[Formula: see text] on structural, thermo-optical and third-order nonlinear optical properties have been analysed through various spectroscopic characterizations. The XRD pattern of the glass (G) exhibits the amorphous nature of the host material while GCs exhibit not only amorphous halo but also the presence of quantum dots (QDs) or nanocrystals (NCs) phases. TEM analysis of the studied GCs samples confirm the presence of quantum dots (QDs) and bulk NCs with an average diameter of approximately 4.2 [Formula: see text] 0.3 nm and 13.4 [Formula: see text] 0.2 nm, respectively. Several phosphate groups were observed and reported from Raman and FTIR-ATR spectra. The absorption band positions confirmed that Ni[Formula: see text] ions resemble to the octahedral symmetry. The intensity of absorption band around 1352 nm ([Formula: see text]TFormula: see text [Formula: see text] [Formula: see text]AFormula: see text) increased with the increase of Ni[Formula: see text] in GCs which is an indicative of the [Formula: see text]Ni[Formula: see text] coordination. The emission properties such as emission cross-sections ([Formula: see text]) full width at half maxima (FWHM) for the [Formula: see text]TFormula: see text [Formula: see text] [Formula: see text]TFormula: see text (visible) and [Formula: see text]AFormula: see text [Formula: see text] [Formula: see text]TFormula: see text (near-infrared) emission transitions were reported. Among the glass-containing semiconductor nanocrystals (GCs), the emission cross-sections in GC4 sample (x = 10% of Ni[Formula: see text]) are the largest for both the visible (11.88 [Formula: see text] 10[Formula: see text] cm[Formula: see text]) and infrared (0.98 [Formula: see text] 10[Formula: see text] cm[Formula: see text]) transitions. Thermal diffusivity (D), thermal conductivity (K) and temperature dependent optical path length change (ds/dT) were obtained through time-resolved thermal lens (TL) and thermal relaxation (TR) methods. The D and K parameters do not change significantly with increase of Ni[Formula: see text] ions (0.5-5%) in GCs. Nonlinear-refractive index and nonlinear absorption of the studied samples were also obtained using femtosecond Z-scan technique. The increase of nonlinear absorption coefficient ([Formula: see text]) is observed from GC2 (2.53 [Formula: see text] 10[Formula: see text] cm/W) to GC4 (7.98 [Formula: see text] 10[Formula: see text] cm/W). The GC4, sample with 10 wt% of Ni[Formula: see text], showed the lowest ds/dT (1.22 [Formula: see text] 10[Formula: see text] K[Formula: see text]) with good lasing (FOM and emission cross-sections) and nonlinear absorption properties suggesting that it can be a good candidate for visible-red emission light conversion in LED technology.
掺杂半导体的玻璃,特别是掺杂纳米结构半导体的玻璃,由于后者具有较大的光吸收截面而受到关注。基于这一特性,通过熔融法和后续热处理制备了掺镍[化学式:见文本](5wt%)的磷酸盐玻璃和掺镍[化学式:见文本]锌[化学式:见文本]碲(x=0.5、1.0、5.0 和 10.0wt%的镍[化学式:见文本])纳米晶(NCs)的磷酸盐玻璃(GCs)。通过各种光谱特性分析了镍[化学式:见文本]对结构、热光学和三阶非线性光学性质的影响。玻璃(G)的 XRD 图谱显示出基质材料的非晶态性质,而 GCs 不仅显示出非晶晕,还显示出量子点(QDs)或纳米晶(NCs)相的存在。研究 GCs 样品的 TEM 分析证实了量子点(QDs)和体相 NCs 的存在,其平均直径分别约为 4.2 [化学式:见文本] 0.3nm 和 13.4 [化学式:见文本] 0.2nm。从拉曼和傅里叶变换-衰减全反射(FTIR-ATR)光谱中观察到和报道了几个磷酸盐基团。吸收带位置证实镍[化学式:见文本]离子类似于八面体对称性。随着 GCs 中镍[化学式:见文本]的增加,在 1352nm 左右的吸收带强度增加([化学式:见文本]T化学式:见文本 [化学式:见文本] [化学式:见文本]A化学式:见文本),这是[化学式:见文本]Ni[化学式:见文本]配位的指示。发射特性,如发射截面([化学式:见文本]),半最大值全宽(FWHM),对于[化学式:见文本]T化学式:见文本 [化学式:见文本] [化学式:见文本]T化学式:见文本(可见)和[化学式:见文本]A化学式:见文本 [化学式:见文本] [化学式:见文本]T化学式:见文本(近红外)发射跃迁均有报道。在含半导体纳米晶的玻璃(GCs)中,GC4 样品(x=10%的镍[化学式:见文本])的可见(11.88 [化学式:见文本] 10[化学式:见文本] cm[化学式:见文本])和近红外(0.98 [化学式:见文本] 10[化学式:见文本] cm[化学式:见文本])跃迁的发射截面最大。通过时间分辨热透镜(TL)和热弛豫(TR)方法获得热扩散率(D)、热导率(K)和温度相关的光程长变化(ds/dT)。随着 GCs 中镍[化学式:见文本]离子(0.5-5%)的增加,D 和 K 参数没有明显变化。利用飞秒 Z 扫描技术还获得了研究样品的非线性折射率和非线性吸收。观察到从 GC2(2.53 [化学式:见文本] 10[化学式:见文本] cm/W)到 GC4(7.98 [化学式:见文本] 10[化学式:见文本] cm/W)的非线性吸收系数[化学式:见文本]增加。GC4 样品(10wt%的镍[化学式:见文本])的 ds/dT(1.22 [化学式:见文本] 10[化学式:见文本] K[化学式:见文本])最低,具有良好的激光(FOM 和发射截面)和非线性吸收性能,表明它可能是 LED 技术中可见光-红光转换的良好候选材料。