In my answers to this question
Day/night cycle science help?1,
and this question
Could this planet exist?2
I discuss factors which could change the relative length of day and night on a planet.
There is a simple geometric reason why normal stars illuminate half of a planet's surface at any one time.
The planet Earth has a diameter of 12,742 kilometers, the Sun has a diameter of 1,391,400 kilometers, 109.19 times as great. So if the Sun and the Earth were touching, the Sun would illuminate a lot more than half of the Earth's surface at any one time. The farther away the Sun was from Earth, the smaller the proportion of Earth's surface it would illuminate at any moment, But even at infinite distance the Sun would still illuminate at least half of the Earth's surface at any one moment.
It is possible for a small white dwarf star or an extremely small red dwarf star to be slightly smaller in diameter than the planet Earth.
But in order to shine they would have to have sufficient density and mass to have many times the mass of the Earth in order to have natural nuclear fusion reactions in their interiors. So even if one could get a red dwarf or a white dwarf small enough to have only the diameter of the Moon, it would still be many times, thousands of times, as massive as the Earth, which in turn is about 81 times as massive as the Moon.
If it was possible to have a shining star that had only the diameter of the moon - and it isn't possible to have a naturally shining star with so small a diameter - it would still have probably at least a hundred thousand times the mass of the Moon and probably be at least a thousand times as massive as the Earth.
So even if a Moon-sized natural star was possible - and it isn't - it would be many times as massive as the Earth, and so the Planet would orbit around the tiny star, not the tiny star around the Planet.
Could any tiny natural star be at the same distance from planet as the Moon is from Earth and yet give that planet the same amount of light and heat as the Sun gives to Earth?
The Sun has an average distance of 149,597,870.7 kilometers from Earth, while the Moon has an average distance of 384,399 kilometers, so the Sun is about 389 times as distant as the Moon. If a star as bright as the Sun was at the distance of the Moon, it would give a planet about 15,000 times as much heat and light as Earth gets from the Sun, and the planet would be many times as hot as Venus or Mercury.
Proxima Centauri is a M5.5V red dwarf star, and is pretty dim for a star. A planet, Proxima Centauri b, has been detected orbiting Proxima Centauri in the habitable zone of Proxima Centauri, at a distance of only about 7,500,000 kilometers and with a day only 11.186 Earth days long.
And even that close orbit is 19.5 times the distance of the Moon from Earth. If a planet was only 384,399 kilometers from Proxima Centauri it would get about 380 times as much radiation as Proxima Centauri b gets and would be hotter than Mercury or Venus.
As far as I know the potentially habitable exoplanet that orbits its star the closest is a planet of TRAPPIST-1, a M8V class star much dimmer than Proxima Centauri. Planet TRAPPIST-1c orbits in the habitable zone only about 2,370,000 kilometers out. But that is still about 6.16 times as far as the Earth-Moon distance, which means that a planet only 384,399 kilometers from TRAPPIST-1 would get about 36 times as much radiation as Earth gets from the Sun.
It is possible that an even more dim natural star could be only about 384,399 kilometers from a planet and give it the same amount of radiation as Earth gets from the Sun.
But that dim natural star would still be about as wide as the Earth and would thus look about four times as large as the Sun and the Moon look from Earth. To make even the smallest possible natural star have the same apparent diameter as the Sun and the Moon, it would have to be moved out to about four times the distance of the Moon, or out to about 1,537,596 kilometers.
And it would be more likely that a natural star could be dim enough to illuminate a planet with only the same amount of radiation as Earth gets from the Sun if that star was at a distance of about 1,537,596 kilometers as it would be if the star was at a distance of 384,399 kilometers.
But that star wouldn't have the diameter or mass of the Moon, it would have about the diameter of the Earth and thousands of times the mass of the Earth. And it wouldn't be at the distance of the Moon.
So IMHO it is almost certain that even if such a dim natural star is possible, it wouldn't satisfy any of your requirements exactly. Though perhaps expert astrophysicists might know of a dim enough star, the diameter and mass requirements seem totally impossible for any kind of a natural star.
Therefore, either you change your requirements or else you need a giant artificial satellite of your planet that has power generation and countless giant lamps.
This artificial "star" or "sun" would be a vast artificial satellite orbiting the planet and containing countless vast fusion power generators that power countless lamps on the surface of the satellite pointed toward the planet and illuminating and heating the planet.
Day/night cycle science help?1