I don't grow sweet peppers but I do grow chilli. I start them in the warm kitchen. No lights. They germinate fast. No special technique. Just pushed slightly into the growing medium. Once they are up they get moved to a warm light spot like a window sill and then on to a cool greenhouse.

I always start mine in a very warm room, with a humidity dome over them. Some people use a heat mat, but I’ve never used one.

I start my seeds in a room on the west side of the house that’s always warmer than the rest of the house due to the afternoon sun. They’re under LED lights and the shelves are under the HVAC vents so they get warm air when the heat is on.

peppers germinate best with a very warm soil temperature - 85 degrees F or so.

Agree with Jamie. I start about 7-10 varieties of sweet and hot peppers every year, and always find they can be slow to germinate compared with other types of nightshades (tomatoes, eggplants, etc).

I've learned to start them in sterile soil under a humidity dome, with a heat map... and just be patient! The sterile soil is important because, with such moist conditions over such a long time, fungus can be a problem.

Germination can vary widely, even within the same variety. For example, this month I have a batch of Padron peppers, all started at the same time, germinate in 6 days, 14 days, and 18 days!

Optimum temperature for pepper germination is 85F. Don't even bother if the temp isn't above 75F. Temperature of the irrigation water doesn't matter. It's the air temperature that determines the temperature of the soil. That all being the case, pepper germination is slow. Takes some time. I don't think the seeds care if there is light. But light shining on them can make things warmer.

I finally got sprouts of all the types planted, will choose one plant for each pot soon. Temps are more like mid 70s in my kitchen. Was hoping to get them up before April, but they are growing.

at 85-90F my peppers sprout about 2-3 days after tomatoes which sprout in about 4 days at 1/8-1/4 in. planting depth.

They will grow LOTS faster is you raise the temperature above the "mid 70s". Like, to 80-90F. If you have them under lights, throw a blanket over the whole setup, and watch the temp. Peppers and tomatoes are slow unless things are really toasty.