It has been well documented that a transistor can be used as diode In this graph, you can clearly see that a 1N2326 germanium diode has very similar characteristics in dropping voltage behavior when compared with a Russian MP20 germanium russian transistor
Red is is the 1N2326 Brown is the MP20 transistor (collector and base are tied together as the cathode
Red is is the 1N2326 Brown is the MP20 transistor (collector and base are tied together as the cathode