Conjuration has a few good ones. The Acid Splash cantrip does 1d3 damage and has unlimited casts (jk, dont use Acid Splash). Corrosive Touch is 1st level and does decent scaled touch damage. Acid Arrow is 2nd level and also does okay damage.
The level 3 spell Explosive Runes is very damaging, abjuration, and also very situational. At level 4 that same school has Fire Trap, less situational, still kind of tricky.
Burning Disarm is a level 1 transmutation that is not necessarily a direct damage effect, but is still effective. Its drop or take some scaled damage, so not a bad trade for you either way.
You can go here and perform a limited, but useful for your specific purposes, filtered search across spells, and see right in the results list where that spell comes from.
Another thing to consider though is why you are concerned about direct damage spells in the first place. There are so many other valuable roles that a wizard can fill, especially with illusion as his school, that its a bit of a waste to focus on damage. Let the evoker sling bolts of fire and force, and you can be buffing the party and debuffing the enemy. Also focusing on solid crafting is good for both of you. The evoker can make wands with metamagic-enhanced combat spells for you to blast away with (hard to interrupt using a wand when you know the spell) while you can make various trinkets and wondrous items with a wide array of practical and pleasant effect for you and the party. Dont get too caught up with the idea of a wizard as a damage dealer. Its possible, but their real strength lies in their insane ability to buff and control the battlefield when well-prepared.