Improvement of dynamic range of filter-less fluorescence sensor with body-biasing technique

Abstract

Although fluorescence microscopy is an important technique in biomedical fields, the bulky equipment is disadvantageous in some situations. We have previously proposed a filter-less fluorescence sensor whose operation is based on the light absorption coefficient, which depends on the wavelength in a silicon substrate. In this sensor, the ratio of the excitation light intensity to the fluorescence intensity is as high as upon optimizing the impurity concentration and the depth of the p-well region. To improve the dynamic range, herein we use a body-biasing technique to optimize the potential distribution of the sensing area to acquire sufficient photocurrent. Consequently, the dynamic range of the filter-less fluorescence sensor is improved to with an 8 V substrate voltage.