Visualization of bandgap energy fluctuation in InGaN quantum wells

•Cathodoluminescence-TEM (TEM-CL) technique was used to analyze light emission from InGaN multi-quantum well structure.•Panchromatic and hyper-spectral image analysis show that light emissions from the InGaN active layers are not homogeneous.•Band-gap energy plot visualizes the energy hump regions where the carriers are preferentially localized.