First off, Hi, I'm Perry, nice to meet you,

to the Dis.
Now with the formalities out of the way, let's get down to business (to defeat the Huns! Yeah, I know, I'm sorry, but really, I'm surprised the Dis doesn't break out into song more often).
Anyway, I must admit that I am the younger sibling out of me and my brother, and it's kinda interesting right now (at least in my POV) because my bro will be going off to college next month.
But my best friend does have a younger brother, and I'm the person he rants to, so while I can't understand it completely I do get it.
Younger siblings can be annoying. You need your space, or to not have to see his face for a couple hours. That's understandable, that goes with everybody in the family.
But unless said younger sibling is being spiteful (and we're not spiteful all the time) or if he's being a tease, usually there's a reason he's annoying you, and he might not even be trying to.
He might just be trying to talk to you or spend time with you, he might be feeling ignored. If that's the case, then do something like every Thursday spend an hour or two playing cards or video games or sports or swimming or put on a movie or something. Set aside some time for him and he might leave you alone. If he's bothering you because he's simply bored, suggest something for him to do (in your nice and patient voice, because showing him you're annoyed will only escalate things) or, again, try spending time with him.
Or you might have accidentally done something or there's a misunderstanding then he could be angry with you, and is retaliating, or he could be angry about something else and taking it out on you. If that's the case, the solution is relatively simple: work it out.
Or he could be suffering from stuck-in-older-sibling's-shadow syndrome, and as he can't take out his frustration at your parents, and often times friends just don't understand, especially when you're young, he might feel forced to take it out on you in order to deal with it. Trust me, stuck-in-older-sibling's-shadow syndrome is one of the worst things that can happen to a younger sibling, I know, I've been through it. My brother is only exactly 14 months older than me, which means he's in the grade ahead of me, and so I've had a lot of his teachers, and I look like him, and so every year a teacher will be like "Oh, are you (bro's name)'s sister?" and I'll be reminded, once again, that they'll expect me to be like my brother, but we're different.
Now I'm not saying that if he is suffering from stuck-in-older-sibling's-shadow syndrome that he is justified in taking it out on you. He's not. He just may not know how to deal with it. He might not show it, but if you have reason to believe he is, I would suggest reminding him he is his own man and it doesn't matter if other people compare him to you.
Of course, it might not be that way, or any of those things. I don't know your family situation. I'm just using reason and logic and my own experience as the younger sibling.
Hope this helps. Feel free to rant some more, it's perfectly fine to rant on the Dis, although do try not to get angry with people on the Dis, that doesn't help anyone and isn't fair.