کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1666991 | 1008837 | 2012 | 6 صفحه PDF | دانلود رایگان |

We report the change in optical absorption properties of InGaN epilayers around the critical layer thickness determined from X-ray diffraction. Detrimental sub-band gap absorption is observed in InGaN thin films grown beyond the critical layer thicknesses, and is caused by localized electric fields around extended crystalline defects and aided by V-defects through light channeling. The photoluminescence response from InGaN thin films, grown beyond the critical layer thickness, is reduced owing to absorption of the incident laser light by non-radiative recombination extended crystalline defects. The formation of V-defects is observed to occur beyond the critical layer thickness and continues to grow in areal coverage aiding in sub-band gap absorption. This optical behavior sets constraints to be incorporated in the design of InGaN solar cell and requirement for improvement in epitaxial growth techniques to reduce V-defects.
► We studied the change in optical absorption of InGaN epilayer with thickness.
► Critical thickness for the optical absorption changes determined by X-ray diffraction.
► The critical thickness reduced with increasing InGaN composition.
► The change in optical absorption is attributed to the creation of V-defects in InGaN.
► The creation of V-defects reduces the photoluminescence intensity of InGaN.
Journal: Thin Solid Films - Volume 520, Issue 22, 1 September 2012, Pages 6807–6812