I am building a transimpedance amplifier circuit. Feedback resistor used is 1 mega ohm. A photodiode is connected to the inverting input of the amplifier (LM741C). Using 23 volt supply, current reading is 32 mA. The current across the resistor, measured with a multimeter shows 23.4 uA. (which makes sense, since V=IR). However, the dark current shows a reading of 4 uA (with all other parameters being the same). Is this a suitable value and if not, what is the mistake I am making?
I have already spent a day searching for any links which could guide me and have not found anything useful. Any help would be appreciated. The link I used for the circuit is Fig.2 of the PDF.