Both Nikon L31 and Samsung ST700 have 16.0 MP resolution sensors but Nikon L31's sensor is 1/2.3' (6.17 x 4.55 mm ) and Samsung ST700's sensor is 1/2.3-inch (6.16 x 4.62 mm ).
Since Samsung ST700's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Nikon L31.
Below you can see the L31 and ST700 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon L31 and Samsung ST700 Cameras
Nikon L31 and Samsung ST700 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.