Hi Ilikemangosalot,
Thanks for reaching out here in the Apple Support Communities. I understand that you'd like make a voice recording at night with as little screen exposure as possible. I'm glad to help with this.
You can use Voice Memos for this. You would only need to look at the screen when starting or ending the recording. You can either lock the screen to hide the display, or turn the iPhone face-down to limit the light you see.
Make a recording in Voice Memos on iPhone
You can also check in the App Store to see if there are other apps that allow you to record your voice without turning on your display.
Best Regards.