The S5973-02 from Hamamatsu Photonics is a Photodiode with Wavelength Range 320 to 1000 nm, Capacitance 1.6 pF, Dark Current 0.001 to 0.1 nA, Responsivity/Photosensitivity 0.30 to 0.42 A/W, Active Area Diameter 0.4 mm. More details for S5973-02 can be seen below.