Electrical, optical, and structural properties of indium-tin-oxide thin films for organic light-emitting devices
Electrical, optical, and structural properties of indium-tin-oxide thin films for organic light-emitting devices
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DOI：
10.1063/1.371708
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发表时间：
1999-12-01
影响因子：
3.2
通讯作者：
Chrisey, DB
中科院分区：
文献类型：
--
作者：
Kim, H;Gilmore, CM;Chrisey, DB
利用脉冲激光沉积技术（PLD）在玻璃衬底上生长出了高质量的铟锡氧化物（ITO）薄膜（200 ~ 850 nm），而无需进行沉积后退火处理。研究了这些薄膜的结构、电学和光学性质与靶成分、衬底沉积温度、背景气体压力和薄膜厚度的关系。薄膜由不同的目标组成，从0到15 wt %的SnO2含量沉积。高电导率的最佳目标组成为5 wt % SnO2+95 wt % In2O3。薄膜在衬底温度范围从室温到300摄氏度，O-2分压范围从1到100 mTorr。利用KrF准分子激光（248nm，半宽30ns）在2j /cm(2)的影响下沉积薄膜。在10 mTorr氧压下室温生长的150 nm厚ITO薄膜，其电阻率为4 × 10(-4) ω cm，在400 ~ 700 nm可见光范围内的平均透射率为85%。在300℃、10 mTorr的氧气条件下沉积的170 nm厚ITO薄膜，其电阻率为2 × 10(-4) Ohm cm，在可见光范围内的平均透射率为92%。在300℃下沉积的150 nm厚薄膜的霍尔迁移率和载流子密度分别为27 cm(2)/V s和1.4 x 10(21) cm（-3）。ITO薄膜折射率的降低可以通过提高薄膜中的电子密度来实现，这可以通过增加靶中Sn掺杂剂的浓度和/或提高沉积温度来实现。原子力显微镜对这些ITO薄膜的测量表明，它们的均方根表面粗糙度（类似于5埃）优于市购的溅射沉积ITO薄膜（类似于40埃）。将所制备的ITO薄膜用于有机发光二极管的制备。测量了这些结构的电致发光，计算出外量子效率为1.5%。(C) 1999年美国物理研究所。[s0021 - 8979(99) 04223 - 1]。
High-quality indium-tin-oxide (ITO) thin films (200-850 nm) have been grown by pulsed laser deposition (PLD) on glass substrates without a postdeposition annealing treatment. The structural, electrical, and optical properties of these films have been investigated as a function of target composition, substrate deposition temperature, background gas pressure, and film thickness. Films were deposited from various target compositions ranging from 0 to 15 wt % of SnO2 content. The optimum target composition for high conductivity was 5 wt % SnO2+95 wt % In2O3. Films were deposited at substrate temperatures ranging from room temperature to 300 degrees C in O-2 partial pressures ranging from 1 to 100 mTorr. Films were deposited using a KrF excimer laser (248 nm, 30 ns full width at half maximum) at a fluence of 2 J/cm(2). For a 150-nm-thick ITO film grown at room temperature in an oxygen pressure of 10 mTorr, the resistivity was 4 x 10(-4) Omega cm and the average transmission in the visible range (400-700 nm) was 85%. For a 170-nm-thick ITO film deposited at 300 degrees C in 10 mTorr of oxygen, the resistivity was 2 x 10(-4) Ohm cm and the average transmission in the visible range was 92%. The Hall mobility and carrier density for a 150-nm-thick film deposited at 300 degrees C were 27 cm(2)/V s and 1.4 x 10(21) cm(-3), respectively. A reduction in the refractive index for ITO films can be achieved by raising the electron density in the films, which can be obtained by increasing the concentration of Sn dopants in the targets and/or increasing deposition temperature. Atomic force microscopy measurements of these ITO films indicated that their root-mean-square surface roughness (similar to 5 Angstrom) was superior to that of commercially available sputter deposited ITO films (similar to 40 Angstrom). The PLD ITO films were used to fabricate organic light-emitting diodes. From these structures the electroluminescence was measured and an external quantum efficiency of 1.5% was calculated. (C) 1999 American Institute of Physics. [S0021-8979(99)04223-1].