Gallium oxide (Ga2O3) thin films were produced by sputter deposition by varying the substrate temperature (T s) in a wide range (T s = 25–800 °C). The structural characteristics and optical properties of Ga2O3 films were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Rutherford backscattering spectrometry (RBS), and spectrophotometric measurements. The effect of growth temperature is significant on the chemistry, crystal structure, and morphology of Ga2O3 films. XRD and SEM analyses indicate that the Ga2O3 films grown at lower temperatures were amorphous, while those grown at T s ≥ 500 °C were nanocrystalline. RBS measurements indicate the well-maintained stoichiometry of Ga2O3 films at T s = 300–800 °C. The spectral transmission of the films increased with increasing temperature. The band gap of the films varied from 4.96 to 5.17 eV for a variation in T s in the range 25–800 °C. A relationship between microstructure and optical property is discussed.

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The study examined the association between low birth weight (LBW) (< or = 2,500 g) and attention deficit hyperactivity disorder (ADHD) in two socioeconomically disparate populations. LBW and normal birth weight (NBW) children from the 1983 to 1985 newborn lists of an urban and a suburban hospital in Southeast Michigan were randomly selected. A total of 823 children, 473 LBW and 350 NBW, participated. Data were gathered in 1990 to 1992, when the children were 6 to 7 years of age. The National Institute of Mental Health Diagnostic Interview Schedule for children-Parent version (DISC-P) was used to elicit information on DSM-III-R diagnoses of simple phobia, overanxious, separation anxiety, oppositional defiant, and ADHD. Teachers' ratings of behavior problems were obtained. LBW was associated with ADHD but not with childhood anxiety disorders or oppositional defiant disorder. The association was stronger in the urban than in the suburban population. Data from teachers' ratings revealed an association between LBW and attention problems. The prognostic significance of the observed psychopathology at 6 years of age requires follow-up assessment as the children mature.

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This study aimed to determine whether LATCH scores assessed by professional staff during in-hospital stays are predictive of breastfeeding at 6 weeks. Participants were English-speaking breastfeeding women, 18 years or older, with healthy singletons. LATCH scores were obtained once every 8 hours on day 1 and daily subsequently until discharge. Data were obtained from hospital charts and telephone interviews on day 4 and week 6 postdelivery. At 6 weeks, 188 of 248 (76%) women were contacted and 66.5% were breastfeeding. LATCH scores were higher among women breastfeeding than those who had weaned. Using receiver operating characteristic (ROC) curves, a score of 9 or above at 16 to 24 hours was the most discriminate of the 5 time periods examined (area under the ROC curve = 0.72). Furthermore, women who met this criterion were 1.7 times more likely to be breastfeeding at 6 weeks than women with lower scores. The LATCH assessment tool is a modest predictor of breastfeeding duration.

A brief review on beta gallium oxide (β‐Ga2O3) nanowires (NWs) and nanostructures (NS) is presented in this article. β‐Ga2O3 is a wide‐bandgap (Eg ∼ 4.9 eV) semiconductor and can be doped with n‐ and p‐type dopants, which can lead to applications in many functional devices. Here, we will first discuss briefly the properties of β‐Ga2O3 in bulk form. Then we will describe the growth of β‐Ga2O3 NWs/NS using various techniques including thermal CVD, MOCVD and laser ablation. The present status of research in the area of nanowire growth will be highlighted in this section. Then we will describe the luminescence properties of β‐Ga2O3 NWs such as photoluminescence (PL) and cathodoluminescence (CL). The origin of various peaks in the PL and CL spectra of β‐Ga2O3 NWs/ NS will be presented, with reference to various experimental studies carried out recently. In the final section, we will describe various applications of β‐Ga2O3 NWs in nanodevices such as field effect transistors (FET), gas sensors and deep‐UV photodetectors. Finally, we will give a conclusion and future perspective of the research in the area of this important semiconducting oxide. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

R. (2021). Recent advances in the growth of gallium oxide thin films employing various growth techniques-A review.