The best way to operate a diode in the reverse-breakdown region in your circuit is by using a voltage regulator 1N5273B zener diode from Microsemi. Its test current is 1 mA. Its maximum power dissipation is 500 mW. Its maximum leakage current is 0.1 μA. This zener device has a nominal voltage of 120 V and a voltage tolerance of 5%. It is made in a single configuration. This zener diode has a minimum operating temperature of -65 °C and a maximum of 175 °C.