Villa will look to overturn a 1-0 aggregate deficit against their Premier League rivals in Thursday's (07.05.26) clash and the coach is certain that the fans will rise to the occasion as the team bids to reach the showpiece in Istanbul later this month.
Emery told TNT Sports: "Usually the supporters in Villa Park create a great atmosphere. Often we feel it strongly. Tomorrow, I think, will be the same.
"We have some experiences before, playing matches, special matches, like tomorrow, because it is the first match since I am here that we are going to play a different match and a unique match.
"Because we played a semi-final two years ago in the Conference League, but we played the first leg at home and the second leg away.
"Last year we played in the quarter-finals against PSG in the Champions League, and we played the first leg away and the second at home, but it was a quarter-final and now it's the semi-final.
"And it's the only semi-final we've played in Europe because, as well, the last semi-final we played was in the FA Cup last year but it was different, because it was one match and in London.
"I think this one is the unique match since I am here that we're going to play, and it's so, so special and of course tomorrow we will need our energy, our gameplan, our confidence, everything.
"But we will need the supporters tomorrow. We will need a special day at Villa Park."
Villa are bidding to reach the Europa League final and also look set to qualify for next season's Champions League via the Premier League, a situation Emery considers to be a "dream" given their difficult start to the campaign.
The manager said: "[We're in a] fantastic moment. Because we are enjoying the process in the season, with two very ambitious objectives that we could face in the beginning [of the season], and we are achieving it.
"To play the semi-final against Nottingham in the Europa League and to be fighting for top five in the Premier League - it was a dream when I arrived here three and a half years ago.
"And at the beginning of the season, how we started poorly in the first month, of course I was worried.
"Now I can feel proud at how we responded, the players, the club as well, and how, through our hard work, we are deserving to be here, deserving to play the semi-final and deserving to fight for the top positions in the league."