The S9981-01CT from Hamamatsu Photonics is a Photodiode with Wavelength Range 320 to 1100 nm, Capacitance 200 to 400 pF, Dark Current 0.01 to 1 nA, Responsivity/Photosensitivity 0.55 to 0.65 A/W, Rise Time 0.5 µs. More details for S9981-01CT can be seen below.