Development of Luxmeter Based on Ba0,25Sr0,75TiO3Ferroelectric Material

摘要

Ba_(0,25)Sr_(0.75)TiO)3 (BST) thin films has been deposited on a Si (100) p-type substrate by chemical solution deposition (CSD) method followed by spin coating technique (at 3000 rpm rotational speed for 30 seconds) and annealing process at the temperature around 850°C for 15 hours. The films show a maximum optical absorption at green light. An I-V investigation on the films results in agreement that the thin films have a photodiode characteristic. Electrical conductivity of the BST thin films is in the range of 2.79 x 10~(-7) to 5.3 x 10~(17) S/cm, it is the range of semiconductor materials. The electrical conductivity and photocurrent increase when the light intensity increases from 1000 to 6000 Lux. A BST thin film has been utilized as a light meter in an ATMega8535 microcontroller since it is sensitive with a light intensity change. Base on calibration and validation curves, a measurement using this microcontroller results in comparable light intensity values with that result from a standard instrument.