I am now sole developer in team. How to take advantage of this situation?

Hi guys,
I work in an IT firm, I love my job and have no issue with it. But recently 2 of my colleague resigned within a period of months and now I am the only guy in the department.
One guy left cause he found a better offer, another resigned due to what they say "management negligence".
Now Since I am the only person in my department, all work and responsibility comes down to me, which is fine. But it's such a good opportunity to not use! But I just don't know how to go about it.
I don't want to quit my job, I am just greedy and want better pay.

PS: I hope you guys wont tell me about morals : D