What are the supplications (duas), remembrances (adhkar), or Quranic verses that help those who suffer from insomnia to sleep?

There is no authentic narration regarding remembrances (adhkar) and supplications (du'as) that aid in sleep. However, a weak hadith has been narrated from Zayd ibn Thabit (may Allah be pleased with him), who complained of insomnia to the Prophet (peace be upon him). The Prophet said to him: "Say: 'O Allah, the stars have set, and the eyes have grown calm; You are the Ever-Living, the Sustainer. O Ever-Living, O Sustainer, cause my eyes to sleep and calm my night.'" And his insomnia departed after he said it. Scholars hold the view that it is permissible to act upon a weak hadith concerning virtuous deeds (fada'il al-a'mal) as long as its weakness is not severe.