The authors of the DCGAN paper tell that they scaled the images to a range of [-1, 1] and used tanh as the activation function in the last layer of the generator. Also use the alpha(slope) of LeakyRelu as 0.2.
So I did these things and got rid of the Dense layers as the authors tell to eliminate the fully connected(Dense) layers.
Then I trained the model for 50 epochs. Each epoch takes around 35 secs on a Tesla K80. Look at the results that I got. Code for DCGAN:- https://github.com/yashk2810/DCGAN-Keras