Crystal engineered semi-polar (11?22) GaN-based UV photodetectors have been fabricated which exhibit two dissimilar photo-responses depending on the crystal quality. The higher crystal quality evaluated via x-ray rocking curve (XRC) exhibited remarkable narrow full width half maximum (FWHM) along [-1?123] and [1?100] of 0.11� (396 arcsec) and 0.28� (1008 arcsec), respectively. Integration of the high crystalline structure with the metal?semiconductor-metal type photodetector resulted in notably lower dark current of 4.6?A. The responsivity value is significantly enhanced from 117 mA/W to 325 mA/W with higher crystalline epilayer. The photo-response of the detector made with the enhanced crystal epilayer is measured to be as low as 170 ms with a recovery time of 241 ms by which is the fastest switching time ever reported in semi-polar (11?22) GaN metal?semiconductor-metal UV photodetector. ? 2020 Elsevier B.V...

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