Is it permissible for the Imam to lead the people in prayer, using his mobile phone to read the Qur’an or to listen and repeat after it, if he has not memorized it?

The congregation should put forward the best reciter among them to lead the prayer. There is no objection to using a Mushaf (copy of the Quran) or a mobile phone for recitation during prayer; in fact, it is obligatory for Surat Al-Fatihah. Imam An-Nawawi نقل (narrated) from Imam Ash-Shafi'i and his companions the permissibility of reciting the Quran from a Mushaf during prayer, even if it takes a long time, and that it does not invalidate the prayer. This is also the view of Malik, Abu Yusuf, Muhammad, and Ahmad. As for Abu Hanifa, he held the view that it invalidates the prayer if one does not know the Quran by heart and recites a significant portion from the Mushaf, his argument being that it requires much thought and action.