Low gap amorphous GaN1-xAsx alloys grown on glass substrate

作者：Yu K M^*; Novikov S V; Broesler R; Liliental Weber Z; Levander A X; Kao V M; Dubon O D; Wu J; Walukiewicz W; Foxon C T

来源：Applied Physics Letters, 2010, 97(10): 101906.

DOI：10.1063/1.3488826

Amorphous GaN1-xAsx layers with As content in the range of x=0.1 to 0.6 were grown by molecular beam epitaxy on Pyrex glass substrate. These alloys exhibit a wide range of band gap values from 2.2 to 1.3 eV. We found that the density of the amorphous films is similar to 0.8-0.85 of their corresponding crystalline value. These amorphous films have smooth morphology, homogeneous composition, and sharp well defined optical absorption edges. The measured band gap values for the crystalline and amorphous GaN1-xAsx alloys are in excellent agreement with the predictions of the band anticrossing model. The high absorption coefficient of similar to 10(5) cm(-1) for the amorphous GaN1-xAsx films suggests that relatively thin films (on the order of I,am) are necessary for photovoltaic application.

• 出版日期2010-9-6