Defending champion Alcaraz won his second major at the All England Club in July and said it would be "great" to play three-time U.S. Open winner Djokovic in the showpiece.
But first, the top-seeded Spaniard will take on another former New York champion, Daniil Medvedev (27), who is also chasing his second title at Flushing Meadows.
"It would be great to play a final against Novak here in New York but we both have really tough semi-finals," Alcaraz said. "But obviously both of us are looking for that potential final.
"Last year I was facing my first semi-final of a Grand Slam. Now I'm facing my fourth one. I feel like I'm a totally different player. I'm more mature. I deal better with the pressure."
Alcaraz has won his last two meetings with Medvedev this year, cruising in straight sets at the Wimbledon semi-finals and the Indian Wells title match.
"The last matches that I played against Daniil I played a tactical game perfectly," said Alcaraz. "I think my game suits well against an opponent like Daniil."
World number three Medvedev had graded his quarter-final performance against Russian compatriot Andrey Rublev (25) a 10 out of 10 and said he will have to reach a higher level when he plays Alcaraz in a bid to reach his fifth major final.
"It needs to be 11 out of 10 because that's how Carlos is, very strong," Medvedev said. "I'm someone who fights a lot, so I want to try to be better, and I need to be 11 out of 10 to try to beat him."
In-form Djokovic will replace Alcaraz as world number one after the tournament and is on the hunt for his 24th Grand Slam title to match Margaret Court's all-time singles record.
He will play his 47th major semi-final against home hope Ben Shelton, a big-hitting 20-year-old who became the youngest American to reach the U.S. Open men's last four since Michael Chang in 1992.
"Ben has been serving some bombs this tournament," Djokovic said. "When his serve is on, he is a very difficult player to play against, especially because he's lefty as well.
"It's logical to expect that most of the crowd would support the home player. That's probably going to be the case on Friday, but I'll be ready for it."
Shelton had never travelled outside the United States until this year but made the most of his first international trip by reaching the Australian Open quarter-finals in January.
Now in his first Grand Slam semi-final in only his fifth appearance at majors, Shelton is up for the daunting challenge of squaring off against Djokovic.
"I think that it's an advantage with my game style, playing someone who's never played me before," he said. "I'm definitely going to try to bring some things to the table that are different and hopefully disruptive on Friday."
