![schematic](https://i.stack.imgur.com/6dHKj.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2f6dHKj.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)

I'm confused about whether zener is on or off due to not being able to know voltage on V0. I tried to find by applying KCL & KVL, but current on the diode (Id) and the resistor (Ir) is not equal to each other. I'm using the shockley diode equation.(Id=Is(e^(Vd/Vt))). This current source being connected to zener diode instead of a voltage source makes something complicated. 
Which way should I follow to find V0?
Hope one can give me a trick.

Thanks in advance.

[![circuit](https://i.stack.imgur.com/z5vOR.jpg)](https://i.stack.imgur.com/z5vOR.jpg)