This is true.
An article from Harvard states, "'Sleep is very important for consolidating memories. In any sort of experimental setting, study results show better performance if you learn material and then sleep on it, instead of remaining awake. So there’s lots and lots of evidence now indicating that sleep promotes memory strengthening and memory consolidation,' says Pace-Schott."
As the quote explains, the benefits sleep has on memory lead to better academic performance. But this is only one aspect of the benefits of an adequate amount of sleep for students.
The University of Pennsylvania produced an article that says, "Sleep actually helps students learn, memorize, retain, recall, and use their new knowledge to come up with creative and innovative solutions."
Something else to keep in mind is when you go to sleep. An article from MIT states, "'When you go to bed matters,' Grossman says. 'If you get a certain amount of sleep — let’s say seven hours — no matter when you get that sleep, as long as it’s before certain times, say you go to bed at 10, or at 12, or at 1, your performance is the same. But if you go to bed after 2, your performance starts to go down even if you get the same seven hours. So, quantity isn’t everything.'”
While getting the specified amount of hours of sleep is important, so is the time when you sleep. According to this article, going to sleep after 2am can have negative affects on performance even if the amount of sleep you are getting is in the correct range.
If you are interested in more information, here is a resource from the University of Pennsylvania about students and sleep: https://recharge.energy/pdf/Student_Sleep_Guide.pdf
Sources:
https://summer.harvard.edu/blog/why-you-should-make-a-good-nights-sleep-a-priority/
https://news.mit.edu/2019/better-sleep-better-grades-1001
https://www.med.upenn.edu/csi/the-impact-of-sleep-on-learning-and-memory.html