Tetras are egg layers with external fertilisation, thus the male needs to be present when the eggs are laid. The driving of the males is what prompts the females to spawn. Thus, females alone will not lay, and even if they did, the eggs would not hatch.
Almost without exception, tetras require very soft acidic water to breed successfully. In good conditions with other water chemistry, they may try to breed, but excessive Calcium, (to a lesser extent, Magnesium), in the water binds to the shell of the eggs making them too tough for the fry to emerge. Water soft enough for most tetras is very unstable and can swing wildly in pH, enough to kill the fish. Unless you know exactly what you are doing, adjusting pH and hardness is best left alone. Neons are notoriously difficult to hatch as they require practically zero hardness to get a decent hatch.
Egglayer fry are very small, and most require either a special liquid fry food, (which is easy to obtain), or cultured infusoria. The fry feed off their own yolk sack for a few days to a week before feeding. When they start feeding, you need to supply a lot, and make sure the water in your breeding tank is kept very clean as the fry are not as tough and adaptable as their parents.
The parents and other fish in the tank will eat the eggs and the fry. If you are serious about breeding egglayers, you really need seperate breeding quarters.
Moonlight is not an issue, most tetras spawn at sunrise.
