Preparation and lithium doping of gallium oxynitride by ammonia nitridation via a citrate precursor route
Preparation and lithium doping of gallium oxynitride by ammonia nitridation via a citrate precursor route
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DOI：
10.1016/j.jssc.2007.04.011
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发表时间：
2007-07
影响因子：
3.3
通讯作者：
S. Kikkawa;Kazuteru Nagasaka;T. Takeda;M. Bailey;T. Sakurai;Y. Miyamoto
中科院分区：
文献类型：
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作者：
S. Kikkawa;Kazuteru Nagasaka;T. Takeda;M. Bailey;T. Sakurai;Y. Miyamoto
通过将柠檬酸加入到硝酸镓水溶液中制备的前体进行氨氮化，获得与六方氮化镓（h-GaN）同构的氮氧化镓。在750°C下制造的氧氮化镓具有少量的镓空位，并且用公式表示为（Ga 0.89 □0.11）（N 0.66 O 0.34），其中符号□表示镓空位。镓空位和取代氮的氧都随机分布在结构中。在750-850°C范围内，空位的数量随着氮化温度的升高而减少。使用另外存在硝酸锂的类似制备，将大约10at%的Li+掺杂到氮氧化镓中，导致在750°C下以Li/Ga<1的原子比随机取代Ga 3+。氧共掺杂锂和取代的纤锌矿型晶格中的氮。这些取代降低了氮氧化镓半导体中的导电性。用类似的方法从Li/Ga的混合物中得到了一种新的氮氧化物Li_2Ga_3NO_4。晶体结构与h-GaN是同构的，并被细化为P63 mc，a=0.31674（1）nm，c=0.50854（2）nm。假设2b位随机占据1/5 O和4/5 N，则2b位的Ga和Li占位率分别为0.6085和0.3915。当新化合物被洗涤超过1 min以去除Li 2CN 2杂质时，其分解为α-GaOOH和α-LiGaO 2的混合物。在254 nm激发下，Li/Ga=1的产物的黄光强度最高。
Gallium oxynitride, isostructural to hexagonal gallium nitride (h-GaN), was obtained by ammonia nitridation of a precursor prepared from the addition of citric acid to an aqueous solution of gallium nitrate. Gallium oxynitride produced at 750°C had a small amount of gallium vacancies, and was formulated as (Ga0.89□0.11) (N0.66O0.34) where the symbol □ stands for gallium vacancy. Both the gallium vacancies and oxygen substituted for nitrogen were randomly distributed within the structure. The amount of vacancies decreased with nitridation temperatures in the range of 750–850°C. Approximately, 10at% Li+was doped into the gallium oxynitride, using a similar preparation with the additional presence of lithium nitrate, resulted in the random substitution of Ga3+in an atomic ratio of Li/Ga<1 at 750°C. Oxygen was codoped with lithium and substituted nitrogen in the wurtzite-type crystal lattice. These substitutions reduced the electrical conductivity in the gallium oxynitride semiconductor. A new oxynitride, Li2Ga3NO4, was also obtained with Li2CN2impurity using similar preparations from a mixture of Li/Ga⩾1. The crystal structure was isostructural with h-GaN, and was refined as P63mc with a=0.31674(1)nm, and c=0.50854(2)nm. The Ga and Li occupancies at the 2b site were refined to be 0.6085 and 0.3915, respectively, assuming that the other 2b site was randomly occupied with 1/5O and 4/5N. When the new compound was washed for over 1min for the removal of Li2CN2impurities, it was decomposed to a mixture of α-GaOOH and α-LiGaO2. The as-prepared product with Li/Ga=1 showed the highest intensity in yellow luminescence among the products under excitation at 254nm.