Low-light-level CMOS image sensor for digitally fused night vision systems

Filter-Free Image Sensor Pixels Comprising Silicon Nanowires with Selective Color Absorption

“…Each array contains 100 × 100 nanowires, and all measurements are conducted at room temperature. The dark current measured from each array is ∼300 pA at a bias of −1 V. The dark current density is therefore ∼3 μA/cm 2 , which is significantly higher than state-of-the-art CMOS devices (3.8 pA/cm 2 ) . We believe this comes from thermal generation due to surface states that are increased by the large surface-to-volume ratio of the nanowires and damage to the silicon crystal structure from dry etching. , We anticipate that the dark current could be reduced by synthesizing the nanowires using alternative methods or by adding passivation layers.…”

Low light level CMOS sensor for night vision systems

“…In addition they share the same limitations as image-intensifiers, such as limited spectral range (up to 850 − 900 ), sensitivity to high illumination and temperature and no color capability. On the other hand, low-light CMOS image sensors (CIS) have many advantages over the image intensifiers [1] [2]. Some of these advantages include: higher reliability, better MTF, small size, low weight, low cost with a standard worldwide production process.…”

InGaAs Nanomembrane/Si van der Waals Heterojunction Photodiodes with Broadband and High Photoresponsivity

“…Broadband photodetectors with spectral responsivity in the ultraviolet (UV) to infrared (IR) range have received considerable interest for applications such as optical communications, imaging, sensing, and spectroscopy. − For example, visible to near-infrared (vis-NIR) photodetectors have been largely employed in optical communication systems, in which the wide spectral bandwidth is used to increase optical data transmission capacity . Light detection capabilities in the infrared range enables image sensors fused with night vision systems. , Moreover, UV–vis photodetectors have been used in biomedical imaging systems and ultraviolet astronomy. − To develop broadband photodetectors, several approaches have been suggested based on different designs of nanomaterials and device structures. − ,− For example, graphene and black phosphorus exhibit great promise as potential active materials for broadband photodetectors. , However, low optical absorbance of graphene results in poor photoresponsivity (6.1 mA W –1 ), and the gapless nature of graphene leads to the problem of high dark current. ,, Two-dimensional (2D) crystals such as transition metal dichalcogenides have a drawback of environmental instability and a challenging issue of large-area, high-yield fabrication of devices. , …”

“…4 Light detection capabilities in the infrared range enables image sensors fused with night vision systems. 5,6 Moreover, UV−vis photodetectors have been used in biomedical imaging systems and ultraviolet astronomy. 7−9 To develop broadband photodetectors, several approaches have been suggested based on different designs of nanomaterials and device structures.…”