. 2021 May 27;11:11088. doi: 10.1038/s41598-021-89956-0

Table 1.

Comparison table of GaN humidity sensors.

Refs.	Fabrication method	Sensing material	Range (%)	Response/recovery time (s)		Sensitivity	Sensor type
⁴	Chemical etching and spray coating	ZnO/Porous GaN	0–60	7/13		161	Diode formation
²	Chemical vapor deposition	Ni patterned GaN nanowire	15–85	22.59/26.16			Diode formation
⁵⁰	Dip coating	3D dandelion like GaN flower	11–97	–		1000	Interdigitated electrodes
⁵¹	Spin coating	GaN Powder	75–95	–		–	Interdigitated electrodes
⁵¹	Spin coating	Ga₂O₃-Na–K Doped	10–85	6/21		500	Interdigitated electrodes
¹⁶	MOCVD	$β$ -Ga₂O₃ nanowires on GaN substrate	35–95	25/45		30	Resistive sheet formation
¹	Chemical method etching from GaCl₃	GaN nanoparticles	4–84	140/130		105	–
¹⁷	MOCVD	$β$ -Ga₂O₃ nanowires on GaN substrate	30–90	24.94/6.24 @ 30% RH		319 in dark	Interdigitated electrodes
¹⁷	MOCVD	$β$ -Ga₂O₃ nanowires on GaN substrate	30–90	1.36/1.8 @ 90% RH		7.3 in UV	Interdigitated electrodes
This work	Pulsed DC magnetron sputtering and inkjet printing	ZnO buffer layer/GaN thin film	0–100 (Linear response)	Impedance	3.5/9	79 kΩ/RH%	Interdigitated electrodes
This work	Pulsed DC magnetron sputtering and inkjet printing	ZnO buffer layer/GaN thin film	0–100 (Linear response)	Capacitance	11/6	8.53 nF/RH%	Interdigitated electrodes