Charge the phone in another room overnight and use a proper alarm clock. Small change, and it takes the decision away from you completely.

What the research says

A narrative review concludes that the links with disrupted sleep in young adults are stronger for device use at bedtime and for addiction like patterns than for total screen time. Alongside it, a validation study in 910 undergraduates built a measure for the specific habit of putting off sleep because of phone use in bed, treating it as distinct from bedtime procrastination in general. Both point at the narrow behaviour this tip targets, though the evidence is observational.

Strength of evidence: one line of research. A single study, or a theoretical account.