Silicon based photodiodes, manufactured by using the ultimate capabilities of both planar technology and high purity silicon have opened the possibility to prepare scintillation probes without photomultiplier tubes, operating with a few volts. This paper investigates the capabilities of such probes, consisting of 1 cm2 photodiodes coupled to larger CsI(Tl) scintillators, in gamma-ray spectrometry. For a 38 mm in diameter and 40 mm height cylindric scintillator, resolutions up to 5.5% at 60Co have been achieved.