共 36 条
Ultra-Sensitive Humidity Sensor Based on Optical Properties of Graphene Oxide and Nano-Anatase TiO2
被引:39
作者:
Ghadiry, Mahdiar
[1
]
Gholami, Mehrdad
[2
]
Lai, C. K.
[1
]
Ahmad, Harith
[1
]
Chong, W. Y.
[1
]
机构:
[1] Univ Malaya, Photon Res Ctr, Kuala Lumpur 50603, Malaysia
[2] Islamic Azad Univ, Marvdasht Branch, Dept Chem, POB 465, Marvdasht, Iran
来源:
关键词:
RELATIVE-HUMIDITY;
LINEAR-RESPONSE;
D O I:
10.1371/journal.pone.0153949
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
Generally, in a waveguide-based humidity sensors, increasing the relative humidity (RH) causes the cladding refractive index (RI) to increase due to cladding water absorption. However, if graphene oxide (GO) is used, a reverse phenomenon is seen due to a gap increase in graphene layers. In this paper, this interesting property is applied in order to fabricate differential humidity sensor using the difference between RI of reduced GO (rGO) and nano-anatase TiO2 in a chip. First, a new approach is proposed to prepare high quality nano-anatase TiO2 in solution form making the fabrication process simple and straightforward. Then, the resulted solutions (TiO2 and GO) are effortlessly drop casted and reduced on SU8 two channels waveguide and extensively examined against several humid conditions. Investigating the sensitivity and performance (response time) of the device, reveals a great linearity in a wide range of RH (35% to 98%) and a variation of more than 30 dB in transmitted optical power with a response time of only similar to 0.7 sec. The effect of coating concentration and UV treatment are studied on the performance and repeatability of the sensor and the attributed mechanisms explained. In addition, we report that using the current approach, devices with high sensitivity and very low response time of only 0.3 sec can be fabricated. Also, the proposed device was comprehensively compared with other state of the art proposed sensors in the literature and the results were promising. Since high sensitivity similar to 0.47dB/% RH and high dynamic performances were demonstrated, this sensor is a proper choice for biomedical applications.
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